Rebuilding the Armed Detective Agency in Yokohama’s IF Timeline

Yuki is an employee of the Transmigration Bureau. Her job is to travel to parallel worlds on the verge of collapse, eliminate the factors causing the collapse, and save the world. One day, she received a new assignment and arrived in the Yokohama of an alternate timeline. Something had gone a little wrong in this world's Yokohama. For instance, her current body was named Yuki Mori, and she was the heir to the mafia. And then, the Armed Detective Agency, which should have existed, was nowhere to be found, the Three-Part Conception, which should have been stable, had turned into a monopoly, and the already incomplete world was on the verge of collapse. And all of this stemmed from Mori Yuki's birth. Yuki wondered: Could she abandon her identity, take the members who had already risen to the mafia's upper ranks, defect, and rebuild the Armed Detective Agency? Chuuya (eyes wide): ...Defect?! I refuse! Yuki: I have a dangerous idea. Dazai: I have a plan to help you. Chuuya: I have a plan to help you too. Fyodor: ...Ahem. I also have a plan to help you. Note: 1. Romantic story. The main pairing is Chuuya and the heroine. 2. The heroine is Mori and Fukuzawa's daughter. There is no male pregnancy. The story contains a Mori and Fukuzawa pairing, so please take note. 3. An original alternate timeline. Everyone is in the mafia. Theme: Saving the world through wisdom