Detective Tanuma finds officer Sansa working at his desk. Tanuma asks about Naomasa, and he replies that he went back to the hospital. Sansa also informs him that he was able to uncover some information about the hospital as he had requested him and it turns out that two years prior to the secure ward was constructed the hospital had been receiving generous donations by a man who goes by Takeshi Kuroiwa. Sansa goes on and says that benefactor holds several positions on several companies and non-profits, but there aren't many public details about him.
Tanuma knows who he is talking about and thanks Sansa for the information. The officer asks him about the envelope he brings with him. Tanuma tells that it is an old case in which he participated years ago, and that there is something he wants to check. From the envelope, Tanuma takes pictures of O'Clock while remembering an advice the hero gave him.
The plot dates back to seven years ago, in Osaka. There, hidden in a parking structure, an illegal underground fighting ring known as the Underground Masquerade is taking place. The spectators, all of them hiding their faces under masks, watch brutal fights in which everything is allowed to win, from weapons to the use of Quirks. Because of this, it is normal for the fighters to need medical attention due to their wounds, but there are also knowledge of some fighters missing.
Surrounding the building are Tanuma and a small Police Force. Tanuma asks O'Clock if he wants him and his boys to raid the place, but the Pro Hero replies that there is no point in that. Faced with Tanuma's confusion, O'Clock tells him that his target is not the event itself, but rather the drug trafficking that occurs there. He has knowledge that the fighters are using quirk-boosting drugs and he is heading there to secure some evidence.
Tanuma then realizes that the police are there to secure an escape route for him after he does what he needs to do there. O'Clock asks if he has any more questions, and the detective says only one: "What’s with the Five O'Clock Shadow?" The hero just smiles and takes off saying he has to look the part. Resigned for not getting an answer, Tanuma relays the new orders.
At the Underground Masquerade, a new match is about to begin. The Ring Announcer introduces The Ripper, a fighter armed with a knife who has won five fights without a single loss. The Ripper is none other than O'Clock in disguise. Then the Ring Announcer introduces his opponent, an exceptional fighter with 20 wins and no losses, the Rapper.
Before the match begins, The Rapper complains that they both have a similar alias. The Ripper tells him that nobody cares about his complaints, but The Rapper replies that he has another, and that is that he is armed with a knife. The Rapper considers that the fights should be hand-to-hand, without weapons. The Ripper taunts him asking if he's afraid of him and his knife, but he denies it and encourages him to come at him, knife and all, as he sticks with his code.
At the ringing of the bell, the Rapper pounces on his opponent, using his Strongarm Quirk to attack with a barrage of punches. The Ripper is thrown against the ring barriers, losing the knife and his mask, and the announcer wonders if the fight is already over, but the Ripper stands up and says that he keeps going. He looks at The Rapper and smiles, stating that since he's a nice guy, he's going to play by his rules and fight weaponless.
This declaration greatly delights Rappa, who praises him as he pounces on him to continue the fight.
- It is revealed that Tanuma worked with Iwao Oguro when he was still the Pro Hero, O'Clock.
- More details about Kendo Rappa's backstory are revealed.
- He served as a pit fighter for the Underground Masquerade under the name "The Rapper".
- One of his fights was against Iwao, who was posing as a pit fighter named "The Ripper" in order to expose the Underground Masquerade's usage of illegal Quirk-based drugs.
Characters in Order of Appearance
- Sansa Tamakawa
- Naomasa Tsukauchi
- Rapt Tokage
- Soga Kugizaki
- Moyuru Tochi
- Kazuho Haneyama (Mentioned)
- Master Beast (Flashback)
- Drunk Lee (Flashback)
- Iwao Oguro (Flashback)
- Kendo Rappa (Flashback)