Tatsuya Shiba

Biodata

Power Progression

• An earlier assessment places his potential strength without restrictions at S+; his actual release later produces SS-rank power 73 97.

History

Childhood and Yotsuba Ties

Tatsuya and Miyuki are biological siblings, born in April and March respectively rather than twins. Baifeng Uesugi grew up in their household after their aunt brought him home, and the siblings came to regard him as their elder brother despite having no blood relationship with him 6 44 65.

During childhood, Tatsuya and Miyuki suffered near-fatal injuries in an enemy attack. Baifeng saved both with healing magic 61. Their later ordeals within the Yotsuba family were arranged by Miya Shiba with the tacit approval of some elders. Maya Yotsuba opposed such conduct internally but initially lacked the authority to prevent it 90.

By the time he enters First High, Tatsuya conceals his Yotsuba affiliation. He later refuses to acknowledge membership when questioned by Katsuto Jumonji and has no desire to return to the clan 5 75.

First High and the Public Morals Committee

Tatsuya enters First High as a Course 2 reserve student, attracting the derogatory label “Weed.” Although Miyuki insists that his academic and combat abilities surpass his placement, he discourages her from discussing his full strength publicly 4.

Miyuki asks the student council to recruit him alongside her. Instead, the council appoints him to the Public Morals Committee. Tatsuya initially intends to refuse, believing his poor practical-test performance makes him unsuitable 10 11 12.

When Gyoubu Hattori dismisses his abilities because of his Course 2 status, Tatsuya challenges him to a mock battle. He wins with a rapid physical approach and a strike that briefly renders Hattori unconscious, without using his CAD 12 13. He subsequently joins the committee as its first Course 2 member 14 20.

His disciplinary work includes stopping Takeaki Kirihara’s unauthorized High-Frequency Blade attack on Sayaka Mibu. He subdues Kirihara, defeats students who interfere with the arrest, and decomposes their magic sequences before activation 19 20.

Discovering Baifeng’s Disguise

Tatsuya becomes suspicious after seeing the disguised Baifeng arrive home with Maya Yotsuba. He also notices irregularities in Baifeng’s spellcasting and seeks information from Mizuki Shibata 20 26.

He ultimately identifies Baifeng through his psions, which remain unchanged despite alterations to his appearance and aura. Baifeng explains that the Demon Hunters are pursuing him and asks Tatsuya to keep his return secret from Miyuki and Mayumi. He also entrusts Tatsuya with the Fool’s World card and Miyuki’s completed Thousand-Li Ice Seal card 30.

Nine Schools Competition

Baifeng makes Tatsuya’s appointment as his assistant a condition of joining First High’s engineering team. Tatsuya’s duties include CAD tuning, training plans, and tactical preparation; after Baifeng is injured, he assumes responsibility for all CAD tuning 29 32 64.

Tatsuya also competes in Monolith Code with Baifeng and Leonhard Saijou. Their first match ends before Leo encounters an opponent, as Tatsuya and Baifeng independently defeat everyone they meet. In the finals, Tatsuya engages Shinkuro Kichijoji and frees Leo from gravity magic, but is then restrained by another gravity spell 55 60.

Following suspicious competition accidents, Tatsuya investigates possible interference with contestants’ CADs. Working with Baifeng, he detects unauthorized alterations during Miyuki’s inspection and helps apprehend the inspector. Kudou identifies the implanted spell as Electronic Cicada 47 64 65.

Tatsuya later purchases intelligence from Haruka Ono and sets out with military associates to confront No Head Dragon. Baifeng contacts him before they arrive, having already dealt with the group 69 71.

Conference-Hall Attack

During the attack on the thesis competition venue, Tatsuya decomposes the invaders’ weapons, allowing the assembled magicians to defeat them. He subsequently destroys a truck attempting to ram the building 94 96.

His military identity is disclosed to the gathered students after information restrictions are temporarily lifted. Major Kazama requires those present to keep it secret, and Tatsuya prepares to deploy in Mobile Armor of his own design 96.

After directing the others toward a shelter, he has Miyuki release his power restrictions and enters battle as an SS-rank magician. He repeatedly restores fallen teammates, while Baifeng’s arrival helps turn the battle in their favor 97 98. When the Demon Hunters appear, Tatsuya follows Baifeng’s instruction to withdraw toward Miyuki rather than hinder him 98.

At the end of the story, Tatsuya declines to accompany Baifeng to the Divine Realm. Baifeng nevertheless resolves his emotional troubles and elevates him to the Demigod realm 100.

Personality

Tatsuya is restrained, analytical, and difficult to provoke. He responds calmly to his reserve-student placement and approaches combat pragmatically: when Hattori objects to losing through physical techniques, Tatsuya argues that a real enemy would not respect a division between magical and physical attacks 4 13.

His subdued manner coexists with strong concern for Miyuki. He protects information about his abilities, maintains her CADs, and immediately searches for her after the conference-hall explosion. He also feels frustration over Kobayakawa’s loss of confidence following sabotage at the Nine Schools Competition 4 27 69 94.

He admires Baifeng and consciously draws on his example when deciding to challenge Hattori. Although described as having lost his emotions, he still expresses loyalty, concern, and gratitude; his emotional troubles are ultimately resolved by Baifeng 12 13 75 98 100.

Abilities & Skills

Decomposition

Decomposition is one of Tatsuya’s two fundamental magical abilities, capable of breaking down targets. Together with Regrowth, it contains enough information to occupy his brain’s entire magical capacity 90.

• Magic Sequence Decomposition: Destroys opponents’ magic sequences before activation 20.
• Counterspell limitation: His Sorcerer Decomposition cannot stop the already-formed attacks in Masaki Ichijo’s barrage; it works on sequences about to activate or spells that have not yet taken shape 61.
• Physical destruction: Shatters the conference-hall invaders’ weapons and reduces an approaching truck to tiny particles 94 96.

Regrowth

Regrowth returns a target to its state before a specified time 90.

• Restores fallen teammates, including those described as having died, so they can resume fighting 97.
• Allows Tatsuya himself to return to life, but repeated revivals inflict excruciating pain. Baifeng reduces his perception during battle to ease that burden 98.

Fool’s World

An Innate Magic designed by Baifeng specifically around Tatsuya’s Decomposition, intended to counter group magical attacks 30.

• Nullifies all magic within a hundred li.
• Decomposes magic whether or not it has already been cast.
• Prevents everyone within range—including Tatsuya—from using magic.
• Remains a preliminary, imperfect version when received.
• Successfully prevents Miyuki from casting during its demonstration 30.

Elemental Sight and Magical Analysis

Tatsuya can examine magical information directly, making him valuable in both enforcement and technical investigation 12 64.

• Reads an unfolding Activation Sequence to predict the spell being cast 12.
• Identifies Kirihara’s High-Frequency Blade as it activates 19.
• Recognizes Baifeng through unchanged psions despite his disguise 30.
• Uses Elemental Sight to detect a virus and other alterations inside Miyuki’s CAD, though he cannot immediately identify every addition 64.
• Uses perception magic to locate the frozen occupants of Blanche’s base and confirm that they remain alive 26.

Martial Arts

Trained under Yakumo Kokonoe, Tatsuya combines rapid movement, throws, and precise strikes 7 13 19.

• Moves quickly enough that observers mistake his physical technique for self-acceleration magic 13.
• Knocks Hattori unconscious by striking a bodily point that triggers a brief loss of consciousness 13.
• Subdues Kirihara with a shoulder throw after briefly immobilizing him with magic 19.
• Remains below Yakumo in their documented sparring session 7.

Magic Engineering

Tatsuya aspires to become a magic engineer and has extensive practical experience with CAD software, tuning, and weapon development 7 27 44.

• CAD tuning: Maintains Miyuki’s CADs and services First High’s competition equipment 27 32 64.
• Armed integrated CAD: Builds Leo’s weapon with suggestions from Baifeng. Its initial forms provide an extended floating blade and an automatic defensive shield 44.
• Flight Magic: Develops a tested but still incomplete version used by Miyuki as a competition trump card 66.
• Research contributions: Proposes using Loop Cast for intermittent nuclear fusion 93.
• Military development: Designs Mobile Armor and is assigned software upgrades and performance testing for the modified Third Eye 30 96.

Equipment / Weapons / Items

• Silver Horn — A specialized CAD identified by Azusa Nakajo. Tatsuya carries it in a holster and practices with the newly purchased holster before operational use 14 28.
• Fool’s World card — Bears an image of an old man holding a staff; supplied by Baifeng to activate Tatsuya’s Innate Magic 30.
• Public Morals Committee armband — Identifies his disciplinary authority despite his Course 2 status 20.
• Mobile Armor — Self-designed military armor deployed during the conference-hall crisis. Its chest contains an energy core, and its leg armor enhances battlefield mobility 96 97.

Relationships

• Miyuki Shiba — Biological younger sister and the person he guards. He maintains her CADs, while she defends his abilities and can remove the restrictions on his power 27 65 71 97.
• Baifeng Uesugi — Non-blood elder brother, childhood rescuer, and personal role model. Supplies Fool’s World, supports him in battle, and ultimately resolves his emotional troubles 13 30 44 61 98 100.
• Maya Yotsuba — Aunt and Yotsuba family head. Seeing her care for the disguised Baifeng helps Tatsuya uncover his identity 20.
• Yakumo Kokonoe — Martial-arts master and source of intelligence about Hajime Tsukasa and Blanche 7 26.
• Mari Watanabe — Committee leader who recruits him for his ability to read Activation Sequences and rejects judging competence through Bloom and Weed labels 12 14.
• Leonhard Saijou — Classmate, Monolith Code teammate, and tester of Tatsuya’s armed integrated CAD 7 44 55.
• Mizuki Shibata — Classmate whose unusual perception assists his investigations into Baifeng’s identity and CAD sabotage 20 32 64.
• Harunobu Kazama — Military superior who briefs him on threats, assigns technical work, and safeguards his identity 30 70 96.
• Kyoko Fujibayashi — Trusted military associate who asks him to arrange contact with Baifeng and later guides the students toward shelter 71 97.
• Katsuto Jumonji — Recognizes his talent and recommends joining the Ten Master Clans through marriage. Tatsuya declines to consider marriage while still at school 75.

Notable Quotes

“If it's meant to simulate a real battle, then any means can be used.” 13

“I know, Master. I just still hope I can reach the same level as my elder brother.” 7