This is a parallel world to the story next door, and the protagonist is still Mori Haruhi.
What would change in the story if Fukuzawa Eri, unaware that she was already pregnant when she heard Mori Ogai say he was going to the battlefield, had chosen to accompany him?
Fifteen years later
Dazai Osamu accidentally got hold of a book and saw the original plot. He looked at how the Three Departments were arranged now:
Day: Special Division for Unusual Powers. Director: Taneda Santoka. Staff: Sakaguchi Ango, Izumi Kyoka, Ayatsuji Yukito, Tsujimura Mizuki, Natsume Soseki (retired)...
Yokohama mayor: Uchiha Eri (Fukuzawa Eri/Mori Eri). Secretary: Haruno Kira. Bodyguards: the Undying Legion
Dusk: Armed Detective Agency. President: Mori Ogai. Members: Edogawa Ranpo, Oda Sakunosuke, Kunikida Doppo, Ozaki Koyo and her boyfriend Iruma Kanichi, Tanizaki Junichiro, Tanizaki Naomi, Miyazawa Kenji, Yumeno Kyusaku
The Armed Detective Agency's young lady: Mori Haruhi. Assistant: Akutagawa Gin
Night: Port Mafia. Boss: Fukuzawa Yukichi. Subordinates: Dazai Osamu, Nakahara Chuuya, Yosano Akiko, Akutagawa Ryunosuke, Nakajima Atsushi, the Azure King and Sasaki Nobuko, Higuchi Ichiyo, Kajii Motojiro, Tachihara Michizo, Hirotsu Ryuro...
Dazai Osamu: "..."
What was there to change? How could everything have gone so far off the rails?
Feeling that this beautiful world was unreal, Dazai Osamu decided to take a dip in the water to clear his head. But before he could act, the pink-haired girl walking beside him took his hand. "Dazai, let's go home together."
Dazai Osamu froze for a moment, then smiled and clasped her hand tightly. "Okay."
So this was his anchor...
Even the wandering stray dog had found a place where he could finally feel at peace.
Theme: A spur-of-the-moment idea. Basically, everyone gets a happy ending. A crossover world.