Tatsuya Shiba

Biodata

Background / History

Tatsuya is the biological son of Tatsurou Shiba and Miya Yotsuba, and Miyuki Shiba’s older brother. Despite this parentage, Maya Yotsuba later establishes an official account identifying him as her own son, supposedly conceived using an egg frozen before her kidnapping 169 182 248.

The Yotsuba Clan feared the destructive power it had brought into existence. According to Yunyi’s explanation, the family ostracized Tatsuya as a “fake” magician while deliberately creating means to control him. Miya originally held that control; Miyuki was subsequently adjusted to become his personal limiter. Maya later confirms that Yunyi’s account of the siblings’ circumstances is true 169 182.

Surgery made Tatsuya an artificial magician and left him emotionally deficient. His instinctive responses toward Miyuki are also altered: when Yunyi deliberately provokes him by grabbing her, Tatsuya attacks despite recognizing the provocation 162 236.

At First High School, Tatsuya places first in the theoretical entrance examinations but enters Course 2, joining Class E. His classification exposes him to the school’s derogatory “Weed” label despite his exceptional technical and combat abilities 1 2 24.

Personality

Tatsuya generally speaks politely and maintains a restrained, often expressionless manner. He initially withdraws from a lunchroom confrontation rather than escalate it, and he avoids prying into Yunyi’s unusual habits without cause. His reserve does not prevent dry humor: repeated recruitment schemes lead him to tell Yunyi, “Whenever you’re around, nothing good ever happens” 2 6 94.

Miyuki’s safety takes precedence over institutional loyalty. Tatsuya rejects Maya’s direct authority by declaring that only Miyuki can order him, and later carries out Yunyi’s demand against the Itsuwa Family to secure her release. Even under that pressure, he remains cautious enough to conceal her abduction from the main family, fearing that a rescue operation could endanger her 181 296 300.

He shares Yunyi’s concern that magicians are treated as tools rather than people. Although he would like to cooperate in changing their status, he recognizes that their national and military positions may make them enemies 208 210 275.

Abilities & Skills

Decomposition

Decomposition is Tatsuya’s principal destructive magic and one of the Yotsuba Family’s concealed trump cards 68 227.

• Decomposes a terrorist’s firearm while rescuing Mikihiko Yoshida 68.
• Provides the basis for Material Burst’s conversion of matter into energy 299.
• Cannot activate when Yunyi’s domain severs his connection to Psions; his attempted Gram Dispersion fails during their rooftop confrontation 293.

Material Burst

Material Burst is Tatsuya’s Strategic-Class Magic, converting matter into energy with destructive power comparable to a nuclear explosion 290.

• Annihilates the American vanguard fleet near Tokyo Bay 290 292.
• Uses the Third Eye CAD and satellite-assisted targeting during the fleet strike 290.
• Requires careful power calculations near populated coastlines: the resulting waves could damage Tokyo and turn the attack into mutual destruction 290.
• Its aftermath catches a plane carrying people important to Yunyi, causing it to crash into the sea and precipitating their open hostility 293.
• Its demonstrated threat subsequently makes American forces wary of concentrating warships in Tokyo Bay 325.

Restoration and Self-Repair

Tatsuya possesses an automatically activating restoration technique and can also restore injuries suffered by others 143 252 304.

• Recovers from repeated potentially lethal blows during his fight with Yunyi 143.
• Reconstructs the badly damaged portion of his arm within moments after Yunyi’s lightning attack 162.
• Restores Masaki Ichijo’s missing arm; the procedure leaves Tatsuya sweating and needing time to recover 304.
• Does not automatically counter every mental effect. Miyuki puts him to sleep with harmless Mental Interference Magic that bypasses the self-repair trigger, although his willpower allows him to awaken sooner than she expects 232.

Elemental Sight

Tatsuya’s special “eyes,” identified as Elemental Sight, allow him to examine magic and individuals beyond ordinary vision 54 222.

• Tracks people through an abandoned factory and detects danger during the terrorist incident at the competition 38 68.
• Examines Kanon Chiyoda after a Parasite possession and identifies life-threatening complications from blood loss 222.
• Detects the technique engraved into Yunyi’s engagement-ring gift 327.
• Does not automatically unravel Yunyi’s unusual magic: even with his sight, Tatsuya can remove very little from its complex Activation Sequences 68.

Flash Cast and Countermagic

Flash Cast reads Activation Sequences directly from Tatsuya’s artificial Calculation Area, allowing him to cast without the usual CAD-mediated process 68.

• Uses Flash Cast to deploy Decomposition while intervening against terrorists 68.
• Employs Flash Cast during his private fight with Yunyi 143.
• Demonstrates Cast Jamming against Seventh High School during Monolith Code, breaking apart an opponent’s magic 99.
• Uses Electric Light when Yunyi provokes his protective instincts toward Miyuki 162.

CAD Engineering and Magic Development

As Silver, Tatsuya is one member of the secret two-person team Taurus & Silver; he explicitly distinguishes himself from the other member, Taurus 73.

• Tunes CADs for Miyuki, Yunyi, and other First High competitors 27 68.
• Compresses Yunyi’s extraordinarily complex Activation Sequences into competition-approved hardware, achieving performance close to Yunyi’s superior military-supplied model 68 73.
• Prepares Miyuki’s Activation Sequence for Inferno 50 53.
• Verifies Cremation’s compatibility with Shizuku Kitayama’s competition CAD and installs its sequence 90.
• Requests that a spell he developed be credited to Shizuku rather than himself; First High ultimately submits it under her name 105.

Physical Combat and Flight

Tatsuya trains under martial arts teacher Yakumo Kokonoe and possesses close-combat ability sufficient to qualify for the Public Morals Committee without a full magical demonstration 12 143.

• Initially fights Yunyi on roughly equal terms in unenhanced hand-to-hand combat 143.
• Crosses the Monolith Code battlefield fast enough for Masaki Ichijo to suspect acceleration magic, although Shinkuro Kichijoji rejects that explanation 99.
• Falls behind once Yunyi more than doubles his speed through magic; afterward, Tatsuya admits that a real duel could have killed him several times 143 144.
• Demonstrates flight when searching below the rooftop for Miyuki and returning to confront Yunyi 294.

Connection to Miyuki

A “contract” connects Tatsuya and Miyuki, enabling him to sense her fear and locate her 222 232.

• Draws him to Kanon Chiyoda’s bedside after he detects Miyuki’s distress 222.
• Helps him pursue Miyuki after she leaves home without him 232.
• Remains intact during her abduction, helping prevent him from losing control 296.

Equipment / Weapons / Items

• Gun-shaped CAD — His regular combat device, carried in a holster. During his first spar with Yunyi, he inserts a “magazine” containing preset Activation Sequences 11 38 304.
• Third Eye — Special CAD delivered by Shigeru Sanada for the Material Burst strike. Its targeting-assistance system links to a satellite through Kyoko Fujibayashi’s support 289 290.
• Home workshop — Contains the equipment Yunyi borrows so Fujibayashi can electronically track Gu Jie 284 285.
• Emotional Resonance ring — One of a matched pair supplied by Yunyi. The engraved technique is intended to connect Tatsuya and Miyuki’s emotions and help restore his emotional capacity; Miyuki immediately places his ring on his finger 327.

Relationships

• Miyuki Shiba / Miyuki Yotsuba — Biological younger sister, the person he guards, and later his fiancée under the family’s revised genealogy. Her safety is his overriding concern, and their connection becomes a means for others to influence him 169 182 294 313.
• Liu Yunyi — Classmate, engineering client, teammate, rival, and eventual enemy. They exchange promises of secrecy and share concerns about magicians’ treatment, but Miyuki’s abduction and Material Burst’s collateral effects fracture their friendship. Tatsuya later describes them as both friends and enemies 74 95 210 293 294 304.
• Maya Yotsuba — Biological aunt and Yotsuba Clan head, later presented publicly as his mother. She arranges his engagement and publicly identifies him as the Strategic-Class Magician responsible for sinking the American fleet 182 248 313.
• Miya Yotsuba and Tatsurou Shiba — Biological parents; Maya’s replacement account of his birth does not reflect his actual parentage 169 248 304.
• Yakumo Kokonoe — Martial arts teacher. Tatsuya compares Yunyi’s relentless attacks to his practice sessions with Yakumo 143.
• Mayumi Saegusa — Student Council president who helps recruit him for school duties and competition. Later invites him and Miyuki to become founders of Yunyi’s proposed new order 12 94 307.
• Mikihiko Yoshida — Class E classmate and chosen Monolith Code teammate. Tatsuya intervenes when terrorists threaten him and prepares his competition CAD 68 94 95.
• Kyoko Fujibayashi — Military associate who supports his Third Eye targeting and calculates a suitable output for Material Burst near Tokyo Bay 290.
• Masaki Ichijo — Fellow competitor and later participant in discussions with Yunyi. Tatsuya restores his lost arm and explains the scale of Yunyi’s threat 114 304 307.

Story Role / Major Arcs

Enrollment and Public Morals Committee

Tatsuya first meets Yunyi after speaking with Miyuki outside First High School. Yunyi already knows his name and entrance-exam standing, an irregularity Tatsuya later recalls when reconsidering why Yunyi approached the siblings 1 195.

A sparring assessment with Yunyi establishes his close-combat credentials and secures his admission to the Public Morals Committee. He subsequently responds to the recruitment-week protest broadcast and joins Miyuki in the frontal approach to an abandoned factory, where he confronts a masked Yunyi without recognizing him 11 12 27 37 38.

Nine Schools Competition

Yunyi’s knowledge of his Silver identity, together with Miyuki’s wishes, draws Tatsuya into First High’s engineering support team. Tuning Yunyi’s CAD proves so demanding that the workload rivals his work for all his other assigned competitors combined 56 68.

He helps investigate No Head Dragon’s interference, preserves Yunyi’s sabotaged CAD as evidence, and later reports defeating the group’s Executors at the exercise grounds 77 78 79 106.

When First High needs substitute Monolith Code competitors, Tatsuya agrees to enter and selects Mikihiko and Yunyi as teammates. Their division of duties places Tatsuya on offense, Yunyi on defense, and Mikihiko in a guerrilla role 94 95.

Yotsuba Revelations and Engagement

After transferring to the Student Council, Tatsuya’s disputes with Yunyi increasingly center on Miyuki. Their private fight exposes how dangerous Yunyi’s enhanced physical combat and Psion-blocking magic are to him 132 143 144.

Yunyi’s revelations about the siblings’ engineered circumstances lead to a confrontation at the Yotsuba main house. Maya confirms the revelations, establishes the account that Tatsuya is her son, and privately engages him to Miyuki. She later presents him to the clan heads as Tatsuya Yotsuba, Miyuki’s fiancé and a Strategic-Class Magician 181 182 313.

Material Burst and Miyuki’s Abduction

During the American attack, Tatsuya deploys Material Burst against the fleet outside Tokyo Bay. Its collateral effects bring down a plane carrying people important to Yunyi 289 290 293.

Yunyi declares them enemies, suppresses Tatsuya’s magic, and abducts Miyuki after pushing her from a rooftop. Unable to recover her, Tatsuya accepts Yunyi’s condition: the destruction of the Itsuwa Family. He carries out the attack while withholding the abduction from the Yotsuba main family 293 294 296 298 300.

Negotiations over a New Order

Tatsuya later restores Masaki’s arm and conveys Yunyi’s warning that Japan will not be allowed to surrender without facing the consequences of the war. He and Miyuki seek a meeting to understand what Yunyi intends to change 304.

Mayumi invites the siblings to help establish a force capable of restraining international conflict. Tatsuya promises to consider the proposal but asks Yunyi to stop actions that intensify the war while he resolves his own obligations 307.

Yunyi subsequently gives the pair Emotional Resonance rings as an answer to an agreement with Miyuki. The gift offers a possible route toward Tatsuya’s emotional recovery, rather than demonstrating that recovery is complete 327.

Notable Quotes

“The only one who can give me orders is Miyuki!” 181

“If we didn’t have different positions, I’d really like to try working with him to see if we could change the status of magicians.” 210

“We’re friends, and we’re enemies.” 304