[Crossover] I Heard He Raised These Kids

My Upcoming Novel: Big Dazai, Little Oda Pairing: Oda Sakunosuke x Dazai Blurb: The time machine in Oda Ryukichi's household has a few bugs. Bug 1: Whenever the swords go out on a mission, Oda Ryukichi is passively bound to the time machine and taken to different worlds. Bug 2: Oda Ryukichi returns from those other worlds along with the swords. The time machine comes with rules that make him forget everything that happened while he was there. One day. Mikazuki: Master, the Time Government sent word that several worlds in the present have fused for unknown reasons. Ryukichi: I see. Will this affect our citadel? Mikazuki: It shouldn't. Ryukichi: I see. Then it's nothing to worry about. One day. Ryukichi told the swords, "Miss Umekawa is getting married. I'm going to her wedding." And so, after arriving in the present, Oda began a bewildering journey of being mistaken for people's family. A brown-haired young man with flames over his head: Dad? No, he's been missing for fourteen years. A young man who can see yokai, taking a cat for a walk: Teacher? No, a great yokai ate him long ago. A blond, burly man hailed as the Number One Hero: Big Brother? No, he was killed in that battle. A young man in a sand-colored coat, wrapped in bandages: Oda Sakunosuke! No, he died in my arms long ago. Ryukichi: I'm sorry, but please accept my condolences. The young men: Sorry, we mistook you for someone else. (Not a chance.) A story about children who grow up still missing someone, while that someone has no idea, and about forming new bonds and becoming a stand-in for an older brother. Please note: 1. The pairing is Dazai. 2. The protagonist is named Oda Ryukichi. Everyone knows him as Oda Sakunosuke. Theme: