Nangong Natsuki

Biodata

Power Progression

Background / History

Nangong Natsuki joins the Special Class as one of two new teachers assigned to accompany its students into another world. She serves as the lead instructor, while Yor acts as her deputy; Natsuki is specifically responsible for teaching magic and handling the group’s overall safety and logistics. 82

During the class’s first transfer, Natsuki uses a purple Space Magic array to teleport everyone to a Dungeon entrance. She later places emergency-return marks on the students, allowing them to teleport back to safety if necessary. 83

After observing Li Yu’s exceptional response to teleportation and his ability to comprehend spatial arrays, Natsuki tests his aptitude by personally teaching him Space Magic. She becomes his primary mentor in the field and continues providing increasingly advanced spatial techniques as his strength grows. 84 129 212 213

While operating in Orario, Natsuki helps manage the Hestia Familia’s expansion. She and Yor secure Haruhime’s release from the Ishtar Familia, arrange for transferred residents to receive housing and identification in their new world, and oversee the relocation of allies from Orario. 125 149 151

She also handles valuable compensation from the Freya Familia, collecting magic books, rare materials, medicinal ingredients, and business assets. Before the group’s departure, she instructs Hestia to preserve the Familia’s Orario base rather than dismiss its employees. Part of her reason for bringing Miach to their world is the possibility of healing injured heroes such as Principal Hu. 149 151

As Boundary University’s Special Class develops, Natsuki reorganizes the students into five-person teams, sets progression requirements for interworld missions, and warns them that they must become stronger if they wish to keep pace with Li Yu. 173 229 232

She subsequently delegates an expedition to Li Yu without accompanying the students, requiring them to manage their own preparations and activities. Later, she announces that the class’s schedule will become less structured, allowing greater freedom for independent training. 174 360

Natsuki also becomes responsible for receiving and integrating people rescued or recruited from other worlds. She adopts Kayo Senju, takes Sakura in as a spatially gifted apprentice, helps settle elves arriving from another world, and provides a home for Sakura and Xia Shi. 205 226 238 247

During the expedition to the Gastrea world, she encourages Li Yu to send rescued children back through their spatial connection. The scale of his takeover of the Tokyo Area surprises her, and she cautions him about opposition from other regions before arriving with additional personnel through the passage. 176 185 186

Her administrative duties expand to infrastructure and technology. She oversees construction of a lunar base, obtains stellar rail technology from Li Yu, helps distribute the Star Destroyers he brings back, and arranges study plans and research placements for newcomers. 357 404 444 445 493 494

When constructing a passage to the Type-Moon world, Natsuki encounters Rin Tohsaka and brings her to their side, reuniting her with Sakura. She later joins Li Yu’s trip to Little Garden with Yor, Shizuka Hiratsuka, and Luo Hao, receiving a Spirit Rank and reaching Tier Ten. 447 502 503

By the time she requests assistance for the world visited by Sakayori Iroha’s group, Natsuki is managing an expanding shortage of dependable forces. She reports that the passage to the A Certain Magical Index world has been sealed again after the magic side begins a world war; Aleister and Aiwass have disappeared, and Academy City is under her group’s management. With Heroic Spirits spread too thin across multiple worlds, she obtains most of Li Yu’s Ex-Machina as reinforcements rather than asking him to intervene personally. 597

Appearance

Natsuki is a petite woman associated with Gothic Lolita fashion. She is first seen carrying a small parasol and later outfits Sakura and Xia Shi in matching Gothic-style clothing. 82 83 247 248

• Often wears Gothic Lolita outfits. 82 101
• Carries a small parasol during her first appearance with the Special Class. 82 83
• Her Space Magic manifests through purple magic arrays. 83 149
• Keeps a home filled with children’s items and clothing after taking in several girls. 248
• Also wears casual clothing at home rather than remaining in her Gothic Lolita outfit at all times. 248

Personality

Natsuki maintains a serious, authoritative demeanor in front of students and takes her responsibilities as an instructor seriously. She gives direct orders, establishes clear strength requirements, and treats interworld travel as a matter requiring preparation and discipline. 82 151 173 232

She is highly practical in negotiations and security matters. When securing Haruhime’s release, she relies on Yor’s strength to ensure the Ishtar Familia cannot resist; when a Dimensional Rift appears, she immediately alerts security forces, evacuates civilians, and begins assessing the threat. 125 212

Despite her strictness, Natsuki actively nurtures gifted students and vulnerable children. She takes special interest in Li Yu’s spatial aptitude, adopts Kayo Senju, accepts Sakura as an apprentice, and works to provide children brought from other worlds with safety, education, and a stable home. 83 205 237 238 248

She is notably irritated when others append “-chan” to her name, particularly Yor and Li Yu. 108 198

Natsuki takes pride in her position as Li Yu’s teacher. Even after his power far exceeds what she can teach him, his public acknowledgment of her as his instructor makes her visibly pleased. At the same time, his rapid growth motivates her to continue pursuing her own advancement. 318 445

Her care for children coexists with initial inexperience: Li Yu notices numerous purchased but unused children’s items in her home. Nevertheless, she adjusts her habits to accommodate the girls, including ceasing to teleport directly into the apartment after Xia Shi explains that her sudden arrivals are frightening. 247 248

She values strategically useful talent and technology, welcoming Emilia’s nearly limitless magical potential and recognizing the benefits of importing advanced knowledge. Her later request for the underused Ex-Machina reflects a preference for practical resource allocation over automatically relying on Li Yu himself. 107 223 404 597

Natsuki trusts her intuition when dealing with unfamiliar people, becoming immediately wary of Elysia’s interest in her. Her security pragmatism also extends to agreeing to relay Li Yu’s proposal to recruit trustworthy races and, if necessary, control dangerous individuals through brainwashing or eliminate them. 494 597

Abilities & Skills

Space Magic

Natsuki is a specialist space mage with exceptional sensitivity to spatial disturbances. Her magic supports transport, evacuation, communication, rift management, and cross-world travel. 83 212 246

• Creates large purple magic arrays capable of teleporting entire groups. 83 149
• Detects when someone observes or interferes with surrounding space. 83
• Places spatial marks on individuals for emergency or remote return teleportation. 83 196
• Teleports across worlds and transports groups from Orario to Boundary University. 149
• Detects Dimensional Rifts and responds directly to unstable spatial points. 212 246
• Opens passages between worlds and offers transit routes to allied groups. 246
• Can cast many Space Magic spells without formulas by the time Li Yu reaches Rank Ten. 318
• Knows and teaches the intermediate spells Space Teleportation, Space Lockdown, and Space Barrier. 84
• Uses Chain of Commandments to condense spatial elements into purple chains that anchor Dimensional Rifts and reinforce weakened space. She explains that spatial elements can take other forms, but prefers chains for stabilization. 213
• Uses spatial marks as anchors for cross-world communication with Li Yu, allowing contact without an ordinary phone connection. 175 176 212

Spatial Law and Authority

Natsuki’s long-term cultivation centers on understanding spatial laws rather than merely increasing her rank. By Rank Eight, she has begun condensing a spatial-law seed; later power growth allows her laws to condense into Authorities before she reaches Tier Ten. 318 475 503

• Her spatial sensitivity allows her to recognize Kiana’s innate Authority of Space. 448
• She reaches Tier Ten after receiving a Spirit Rank. 503
• Her advancement is linked to her sustained study of space and spatial laws. 318
• Understands the distinction between world-dependent power and an independent path, explaining to Li Yu that reaching Tier Ten requires developing one’s own rule rather than relying too heavily on a world. 280

Magical Instruction

Natsuki trains students in magic and establishes requirements for their development before they enter dangerous worlds. 82 129 173

• Tests Li Yu’s learning talent by teaching him the foundations of Space Magic. 84
• Promises to teach Li Yu advanced Space Magic after he reaches Tier Five. 129
• Teaches Li Yu the spatial spell Chain of Commandments to anchor and stabilize a Dimensional Rift. 213
• Arranges for Bell and Haruhime to study magic based on their respective aptitudes. 126
• Assigns Mahiru Shiina to learn healing magic after identifying her healing-related talent. 173
• Teaches Lefiya meditation as a method of restoring and expanding magical reserves, introducing a practice distinct from Orario’s focus on mind power. 110
• Teaches the class Weapon Storage and Piercing Magic, forbidding mana-potion recovery during that training to encourage development of their natural recovery ability. 135
• Explains the operational logic of Intermediate Magic in the university’s formal lessons. 174
• Offers to pass on all of her remaining Space Magic to Li Yu once his strength is sufficient; she later acknowledges that he has already learned her spatial techniques. 230 237
• Begins attempting to learn Li Yu’s method for creating a second source of magical power, though the context does not confirm its completion. 248

Interworld Administration and Deployment

Natsuki coordinates personnel, accommodations, documentation, alliances, and infrastructure across connected worlds. Li Yu leaves Familia alliance decisions to her, and she later oversees increasingly complex technological and military arrangements. 135 151 226 357 493 597

• Arranges housing and identity documents for Orario arrivals and later for Emilia’s group. 151 228
• Organizes reception and settlement for incoming elves, including a banquet and plans for further education. 226
• Oversees construction of the lunar base. 357
• Acquires stellar rail technology materials and offers Li Yu a share of the associated stock. 404
• Coordinates the distribution of imported Star Destroyers to locations where they are needed. 493
• Receives information about Sakayori Iroha’s destination world directly from Li Yu’s memories. 597
• Gains an AI link from Einzig that allows her to deploy borrowed Ex-Machina forces, including through teleportation. This provides operational access rather than a stated increase in her personal cultivation level. 597

Limitations

• A large, long-distance group teleportation exhausts her magical reserves during the journey to the Type-Moon passage facility, requiring her to drink a Blue Potion. This occurs before her later power increases. 233
• Her attempt to teleport Li Yu after his God Slayer transformation fails when his passive magic resistance destroys the array. She instead tells him to return independently. 230
• Her administrative reach depends on available personnel: the shortage of Heroic Spirits across multiple worlds eventually leads her to seek Ex-Machina reinforcements. 597

Equipment / Items

• Small parasol — carried during her introduction to the Special Class and during early teleportation operations. 82 83
• Phone — used to receive coordinates, communicate with Li Yu, and coordinate responses to spatial incidents. 212 446
• Spatial marks — magical marks placed on travelers to enable return teleportation and remote contact. 83 175 196
• Blue Potion — used to restore her mana after an exhausting group teleportation. 233
• Stellar rail technology materials — received from Li Yu for technological development. 404
• Ex-Machina AI link — supplied by Einzig, granting operational access to the forces Li Yu lends her and enabling their deployment by teleportation. 597

Relationships

• Li Yu — Student and principal spatial-magic disciple. Natsuki recognizes his extraordinary spatial talent, teaches him her techniques, and relies on him for high-risk interworld assignments. 83 84 212 230 She remains pleased that he acknowledges her as his teacher despite surpassing her, and their cooperation expands to sharing technology, information, and military resources. 404 445 493 597
• Yor — Fellow teacher and deputy during the class’s early expeditions. They work together on student supervision and recruitment, though Natsuki repeatedly objects to Yor calling her “Natsuki-chan.” 82 108 124 Both reach Tier Ten during their visit to Little Garden. 503
• Shizuka Hiratsuka — Colleague and fellow instructor. Natsuki coordinates Special Class teaching and expedition management with her. 83 172 404
• Hestia — Ally and liaison to the Hestia Familia. Natsuki assists with Familia recruitment, relocation, and negotiations in Orario. 125 141 146
• Kayo Senju — Adopted daughter. Natsuki promises to raise and train her according to Kayo’s own preferences. 205
• Matou Sakura — Apprentice with exceptional spatial affinity. Natsuki takes Sakura in, teaches her Space Magic, and provides her a secure home. 237 238 248 403 Sakura becomes happier and more confident under her care. 447
• Xia Shi — Child living in Natsuki’s household alongside Sakura. Her discomfort with Natsuki suddenly teleporting into the apartment leads Natsuki to begin entering through the building normally. 247 By a later visit, Xia Shi has begun learning Intermediate Magic. 447
• Luo Hao — Colleague whom Natsuki brings to Little Garden in hopes of resolving her incomplete God Slayer status. 502 503 Li Yu credits Natsuki’s reminder for the opportunity, and Luo Hao promises to remember both of their help as a life-changing kindness. 503
• Lefiya — Mage from the Loki Familia whom Natsuki teaches meditation to improve magical recovery and reserves. 110
• Emilia and the relocated elves — Newcomers whose reception, settlement, documents, and educational arrangements Natsuki helps organize. She regards Emilia’s nearly limitless magical potential as a major future asset. 223 226 228
• Rin Tohsaka — Sakura’s older sister, whom Natsuki encounters while constructing the Type-Moon passage and brings to their world. Rin is present in Natsuki’s apartment when Li Yu visits. 447
• Mei, Syr, Bronya, and Kiana — New arrivals entrusted to Natsuki for study plans and integration after Pandora informs her of their circumstances. 444 445 Natsuki detects Kiana’s Authority of Space and discusses her clone origin and psychological well-being with Li Yu. 448
• Elysia — A newcomer whose immediate interest in Natsuki causes her to become wary and avoid engaging with the attention. 494
• Pandora — Informs Natsuki about incoming people and is associated with the descending will that grants the visiting teachers Spirit Ranks in Little Garden. 444 503
• Einzig and the Ex-Machina — Reinforcements borrowed from Li Yu to address shortages across connected worlds. Einzig provides Natsuki with an AI link and operational access to most of the Ex-Machina, while some remain with Li Yu. 597

Story Role / Major Arcs

First Orario Expedition

Natsuki leads the Special Class’s initial journey to the DanMachi world, establishes emergency return measures, and begins identifying Li Yu as a potential Space Magic successor. 82 83 84

Hestia Familia Expansion

She supports the Hestia Familia’s growth by helping recruit Haruhime, negotiating with hostile Familias through Yor’s deterrence, and arranging the transfer of Orario residents to Boundary University’s world. 125 141 149

Her work also includes handling alliance decisions, securing compensation and assets, and ensuring that the Familia’s Orario base remains staffed and usable after the relocation. 135 149 151

Special Class Reorganization

As homeroom teacher, Natsuki reforms the class into five-person teams, assigns training roles, and institutes Tier Five as the minimum qualification for an upcoming interworld mission. 151 173 229

She entrusts Li Yu with leading an expedition without teacher accompaniment and later allows the students more freedom to train independently, while continuing to warn that insufficient strength will exclude them from higher-level missions. 174 232 360

Dimensional Rift Management

Natsuki becomes a central responder to Dimensional Rifts, evacuating civilians, teaching Li Yu stabilization techniques, and coordinating exploration or passage-building across worlds. 212 213 246

After Li Yu is drawn into the Demon Slayer world, she opens an exit from Infinity Castle and offers the Demon Slayer Corps a route to their world for alliance discussions. She subsequently helps report the incident to Principal Hu and accommodates Li Yu while the rift in his dormitory is being handled. 246 247

Guardian of Rescued Children

She takes responsibility for children brought back from other worlds, adopting Kayo and raising Sakura and Xia Shi while providing magical education and a stable household. 205 238 247 447

During the Gastrea expedition, she coordinates the reception of rescued children and additional personnel. Later, her passage-building work brings Rin Tohsaka to their world and enables the sisters’ reunion. 176 185 186 447

Tier Ten Breakthrough

After receiving an enhancement fueled by divine corpses obtained from Little Garden, Natsuki’s spatial laws condense into Authorities and her strength approaches Tier Ten. During a later visit to Little Garden, a descending will grants her a Spirit Rank, allowing her to complete the breakthrough alongside Yor. 474 475 503

She also brings Luo Hao on the trip, helping secure the restoration of her incomplete God Slayer constitution and the removal of its restrictions. 502 503

Interworld Infrastructure and Recruitment

Natsuki oversees the lunar base’s construction and helps incorporate imported technology into her world. Her dealings with Li Yu include an enhancement-potion formula exchanged for assistance with Abant, stellar rail materials, and the deployment of Star Destroyers. 357 360 404 493

She also arranges education for Mei’s group and escorts resurrected Heroic Spirits who choose to work at the research institute, continuing her role as a bridge between Li Yu’s expeditions and the institutions that receive their results. 444 445 494

Academy City Administration and Ex-Machina Reinforcements

Natsuki reports that the A Certain Magical Index passage has been sealed again following a world war initiated by the magic side. With Aleister and Aiwass missing, Academy City is managed by her group, while Heroic Spirits are stretched across too many worlds to meet every need. 597

Seeking help for Sakayori Iroha’s destination world, she obtains Li Yu’s memories and requests the Ex-Machina rather than his direct intervention. Li Yu instructs Einzig to lend her most of their forces, and she receives the AI link needed to deploy them. She also agrees to relay his proposal to expand their dependable personnel through trustworthy races and use coercive measures against dangerous individuals if necessary. 597

Trivia

• Natsuki’s preferred aesthetic is Gothic Lolita fashion; she extends this preference to Sakura and Xia Shi’s clothing. 247 248
• She repeatedly objects to being called “Natsuki-chan.” 108 198
• Although she is initially surprised by Li Yu’s growth, she continues seeking her own breakthrough rather than remaining content at Rank Eight. 318
• Li Yu regards her as his magic teacher and publicly introduces her as such to newcomers. 494
• She enjoys black tea and keeps tea leaves she considers precious, scolding Li Yu and the girls for using them. 176 404
• It took her several months to learn the intermediate spatial spells that Li Yu masters after a single lesson. 84
• When she takes Sakura home, she asks the girl to call her “Sister Natsuki.” 238
• Her Ex-Machina access is acquired to solve an administrative and military manpower shortage, not as a new personal power breakthrough. 597