The Master Assassin Thinks Something Is Off

Natsukawa Sakura is an excellent Animus player and Assassin. She made it all the way to Yokohama, and just as she was about to unlock the memories of an ancestor from the Taisho era, Natsukawa noticed something was off: I thought I'd come to the Taisho era, so what's with these five buildings in front of me? -- After finally retiring from his position as boss, Dazai felt relieved and was about to take that final step when a grown man suddenly appeared in front of him without a sound. The guy acted like they were old buddies: Hey, man, are you here to take a Leap of Faith too? Come on, if we're brothers, let's jump together. Taken by surprise and dragged into jumping off the building, Dazai somehow ended up in the Taisho era: ??? -- Natsukawa Sakura has recently been puzzled by something. Animus glitches are nothing new, but why is there someone who looks exactly like an Assassin colleague she met in the game? Are the genes of pure-blooded Japanese people really that strong? Natsukawa Sakura invited the Assassin descendant in front of her: Hey, fellow Assassin, come on. Let's take down those little Templars together. Dazai, who was just about to leap down: ??? -- Pairing with Dazai, or no pairing. Third-person narration, with an Assassin cheat, and no Mary Sue plot. Mainly Bungo Stray Dogs, with Demon Slayer and Assassin's Creed along for the ride. Any out-of-character writing is on me. Writing this out of love is the best. Theme: Stealing Boss Dazai's lunchbox is victory