Aki Hayakawa

Biodata

Background / History

Family and pursuit of the Gun Devil

Aki’s parents and younger brother were killed by the Gun Devil during his childhood. Their deaths left him hostile toward devils and determined to avenge his family 12.

He specifically sought admission to Tokyo Public Safety, despite Chiba Public Safety already showing interest in him. Tokyo held the largest collection of Gun Devil flesh among Japan’s Public Safety branches and offered access to intelligence about the devil. Aki had learned that gathering enough fragments could reveal the location of its main body; joining Public Safety would also allow him to possess those fragments legally 18 21.

Private hunting in Chiba

When Aki meets Asaba Kotone, he has worked as a private hunter for only a few months but has already killed more than a dozen devils, mostly relatively weak ones. He initially insists that he needs no partner. A guild attendant encourages him to reconsider, explaining that Public Safety evaluates cooperation as well as hunting achievements 12 13 14.

After witnessing Asaba’s strength and composure, Aki proposes a partnership. They register together so that subsequent kills count toward both hunters’ records. Aki then asks Asaba to help him take assignments frequently enough to secure recruitment by Tokyo Public Safety 13 14 16.

Asaba gives Aki the recovered fragment in anticipation of his recruitment. With Tokyo Public Safety’s offer secured, Aki invites Asaba to a farewell dinner. The following morning, Aki accepts the offer and leaves with its representative, while Asaba remains in Chiba 21 22.

Tokyo Public Safety

Aki joins Special Division 2 and becomes Himeno’s partner. He supplies Captain Takeuchi Hirachi with Asaba’s phone number, enabling Public Safety to arrange an inspection of the Jealousy Devil’s corpse. Aki and Himeno subsequently collect the body from Asaba 36 37.

When Asaba later decides to join Public Safety, Aki relays the request to his superiors, who approve it immediately. He and Himeno pick Asaba up, and Asaba is assigned to work alongside them in Special Division 2 49 50.

Appearance

• Young and handsome: Asaba recognizes him as a younger, inexperienced version of Aki 12.
• Reserved expression: Frequently described with an expressionless face, cold eyes, and an aloof demeanor 12 37.
• Back-mounted weapon: Carries the Curse Devil’s sword-shaped nail strapped to his back 12 50.

Personality

Aki is guarded, solitary, and intensely focused on revenge. He initially rejects both partnership and Asaba’s belief that a devil can be a companion. His urgency drives him to seize jobs quickly and compete even with hunters working overnight shifts 12 14 17.

His reserve does not prevent concern for others. He rushes into the library to help trapped civilians, checks on Kobeni afterward, and offers compensation when his contract consumes a shared target’s corpse. As his friendship with Asaba develops, he trusts Asaba’s judgment in combat and warns him that Public Safety work is more dangerous than private hunting 14 15 16 20 22.

Aki refuses Himeno’s attempts to introduce him to smoking, stating that it “rots your bones” and rejecting the idea of smoking merely to get along with others. He does drink alcohol and becomes more talkative when intoxicated 22 37 38.

Abilities & Skills

Fox Devil Contract

Aki can summon the Fox Devil’s head to bite or swallow a target 14 19.

• Activation: Forms a fox-head shape with his right hand and uses the call “Kon!” during the Bookshelf Devil fight 14.
• Payment: Offers flesh or hair each time he uses the power; no initial payment was required when establishing the contract 42.
• Recovery: Flesh payments can require several days of recovery, limiting how frequently he can hunt alone 14 16.
• Variable cost: Letting the Fox Devil eat a target can improve its mood and reduce the price it demands 14.
• Limitations: Decapitation does not stop the Gun Devil-enhanced Carp Devil from regenerating. The summoned head can also be injured, and the contract does not guarantee continued assistance against dangerous opponents 19 20 35.

Curse Devil Contract

Aki possesses a weapon obtained through his contract with the Curse Devil. Its power produces a guaranteed-death effect but consumes part of his lifespan 12 50.

• Restricted use: Aki reserves it for situations where he has no other choice 50.
• Combat contingency: During the Carp Devil battle, he considers using it if Asaba cannot win and the team cannot escape 20.
• Limitations: The death effect cannot permanently eliminate weapon humans capable of reviving with sufficient blood 12.
• Current usage: Aki confirms that he has never used the weapon as of Chapter 50; Himeno urges him never to use it 50.

Hunting and Teamwork

• Established record: Kills more than a dozen devils within his first few months as a private hunter 14.
• Contract management: Alternates fighting duties with Asaba to reduce the strain of Fox Devil summons 17.
• Tactical restraint: Recognizes that another Fox Devil attack would accomplish little against the regenerating Carp Devil and holds back while assessing the situation 20.

Equipment / Weapons / Items

• Curse Devil weapon — A long nail shaped like a sword, carried on his back 12 50.
• Gun Devil flesh fragment — A fingernail-sized, bullet-like fragment recovered from the Carp Devil and given to him by Asaba 21.
• Mobile phone — Used to coordinate assignments with Asaba after they exchange numbers 17 19.

Relationships

• Asaba Kotone — Former private-hunting partner, close friend, and later Special Division 2 teammate. Asaba saves him from the Carp Devil and intends to protect him from Makima’s control 14 20 22 49 50.
• Himeno — Senior and Public Safety partner. Their familiarity grows from her calling him “Hayakawa” to “Aki”; Asaba observes that she already has feelings for him, though they are not established as a couple 37 49 50.
• Ouchihara and Ryoko Yamada — Fellow private hunters who join his team for the Carp Devil assignment 19 20.
• Pochita — Asaba’s devil companion. Aki initially reacts with disgust and cannot understand treating a devil as a friend 12.
• Gun Devil — His family’s killer and the central target of his revenge 12 21.

Notable Quotes

“I'm not interested in any of that. All I care about is killing the devils I want to kill.” 12

“No trouble. Either it dies, or I do.” 12

Trivia

• Aki’s Affinity Album page unlocks when Kobeni’s affection reaches 50%. His entry activates upon meeting Asaba again in Chapter 49, starting at 40% affection 44 49.
• That activation awards Asaba, not Aki, Constitution +1 for the entry and Constitution +4 for the existing affection milestones 49.