Atsushi Nakajima vs. Kyōka Izumi

Atsushi Nakajima vs. Kyōka Izumi is a battle fought between Armed Detective Agency member Atsushi Nakajima and Port Mafia assassin Kyōka Izumi during the Mafia's bounty hunt for the weretiger.

It happened in a train during broad daylight through a bombing incident instigated by Mafia member Motojirō Kajii to lure out Atsushi among the train passengers.

Prologue
Atsushi accompanies Akiko Yosano on a shopping trip throughout Yokohama. Along the way, Atsushi comes across a girl in kimono and briefly exchanges glances with her. Meanwhile, after two failed attempts in capturing Atsushi, the Mafia sends Motojirō and Kyōka – the girl whom Atsushi encounters – to bomb a train that contains Atsushi and Yosano on their way back to the Agency.

After setting off a bomb that claims at least two lives, the mafioso responsible calls Atsushi to surrender in exchange for sparing the lives of the other passengers. Yosano and Atsushi then split up to search for and defuse the remaining bombs; Yosano takes up the front of the train and Atsushi the back. As members of the Agency, they also mutually agree to take on the enemy should they encounter them.

Battle
While Atsushi anxiously looks for the bomb, the girl in kimono bumps into him from behind. He informs her of a bomb in the train, but she coldly attacks him instantly upon receiving orders from her phone to do so. Atsushi sees a katana-wielding phantom, which turns out to be the girl's ability that attacked him. Demon Snow lands swift successive attacks on Atsushi as ordered by the voice on the phone, an ability Atsushi thinks is too powerful.

The girl introduces herself as Kyōka, an orphan who killed 35 people within six months after being taken in by the Mafia. While Atsushi is in disbelief, the voice commands her to keep the bomb at bay and to kill anyone who gets in the way, compelling Demon Snow to attack Atsushi once more and pin him up the wall. Sustaining various injuries, Atsushi notices the passengers onboard and muses whether it is his fault again for getting them into misfortune, recalling the people who spited him for being a bringer of calamity on others.

Nonetheless, the prospect of saving the train passengers in order to prove himself otherwise worthy of living, which he admits may be a foolish idea, drives Atsushi to stand back up and face Kyōka. Though he manages to dodge Demon Snow's quick attacks, he eventually deems it too fast to evade by himself and hopes that his power activates like before. To his surprise, his arm transforms into a tiger limb and blocks Demon Snow's attack.

Demon Snow soon launches multiple attacks, all of which Atsushi efficiently dodges. He rids Demon Snow of its katana which gets lodged to a train post and points his tiger arm at Kyōka, asking her to deactivate her ability and divulge the bomb's location. Kyōka reveals the bomb hidden underneath her kimono. Shocked at how emotionless she is akin to a killing machine, Atsushi questions whether she truly prefers doing such things.

Aftermath
Yosano calls Atsushi through the train's PA system and tells him of a remote detonator that can defuse the bomb at his end, information she acquired from interrogating Motojirō. Kyōka hands the detonator to Atsushi, and he presses it to deactivate. However, the bomb starts ticking, and the voice on the phone instructs her to die along with the bomb's detonation to show the Mafia's formidability. Atsushi asks Kyōka to take it off, but she pushes him away and heads near the train's exit door.

Atsushi then realizes that her ability acts according to the voice on the phone rather than her own volition. Kyōka admits that she wishes to stop killing, before she jumps off the train. With his tiger speed, Atsushi jumps from the train and rips the bomb off her. He shields her from the blast, after which they plunge down the water and arrive by the water bank.

They soon return to the Agency office, where Kyōka is treated by Yosano in the infirmary. Doppo Kunikida also discusses her fate with Atsushi, deliberating on what to do with her given her wanted status.