Jun'ichirō Tanizaki vs. Ichiyō Higuchi

Jun'ichirō Tanizaki vs. Ichiyō Higuchi is a battle fought between Armed Detective Agency member Jun'ichirō Tanizaki and Port Mafia operative Ichiyō Higuchi during a feint request operation by the latter for the Agency.

It happened at a secluded back alley between two buildings as planned by Higuchi to trap Tanizaki, Naomi Tanizaki, and Agency rookie Atsushi Nakajima upon orders of the Mafia during their bounty operation for the weretiger.

Prologue
Shortly after Atsushi's successful entrance exam in the Agency, a client requests an investigation operation for the Agency to stake her workplace's back alley, where she claims that someone in ragged clothing who speaks a foreign tongue has been lurking discreetly. Doppo Kunikida surmises that they might be a smuggler, so the client asks for them to look for whatever evidence she can present to the police for an official report.

Kunikida assigns Atsushi and Tanizaki to accompany the client, with Naomi volunteering to go with them. Before departing, Kunikida and Osamu Dazai advise Atsushi about the Port Mafia's attack dog Ryunosuke Akutagawa, an gifted mafioso with a dangerous offensive ability. As the four leave the office, Dazai listens with his headphones, telling Kunikida that he is "awaiting a divine revelation".

The client, Higuchi, soon brings the Agency members to a dead-end back alley. Tanizaki finds the place strange and suspicious, thinking that outlaws such as their target tend to have an evacuation route to escape, unlike the place they are in. Putting her hair up and donning tactical sunglasses, Higuchi admits luring them into a trap and contacts Akutagawa that she has captured their targets, much to Tanizaki's shock.

Battle
Higuchi, revealed to be a Port Mafia operative, fires at the group with a pair of submachine guns. Naomi shields her brother with her body, leaving Tanizaki and Atsushi bewildered at the sight. As she collapses, Tanizaki panics on how to treat her with first aid, stammering that they must immediately bring her to Dr. Yosano. Higuchi points her gun at Tanizaki to finish him off, but he gets overcome with anger and activates Light Snow.

As Higuchi is confused with the snow falling, Tanizaki asks Atsushi to take cover while he deals with their opponent. Higuchi shoots at Tanizaki, but he suddenly dissipates as the bullets hit him. He explains the nature of his ability that turns the entire snow-filled space into a screen, where his body is overwritten within the scenery.

Unable to locate him, Higuchi fires through all directions in an attempt to shoot him, but Tanizaki emerges from behind and strangles her. However, Tanizaki is attacked from behind by Akutagawa, who rejoins Higuchi with capturing Atsushi due to a bounty placed on his head.

Aftermath
Atsushi is left fully conscious during the skirmish, compelling him to face Akutagawa amidst the injured Tanizaki's instructions for him to run away, as well as Kunikida's earlier directive to flee instantly should he encounter Akutagawa.