They Say Evil Expects Evil From Other's

Two siblings bound by blood and a violent history-Osamu Dazai, famed for his irreverent wit and lethal cunning, and Haruko Dazai, whose beauty masks a formidable ability-are reluctantly drawn back into the city's power struggle. The Port Mafia and the Armed Detective Agency must join forces once again, and Osamu and Haruko find themselves stuck in the middle, despite a past they've been trying to forget. The few who once supported them show themselves again, bringing old loyalties into question and exposing secrets that could destroy Yokohama. As alliances shift, the siblings must wrestle with their emotions, and Haruko must learn how to become one with her ability. Can they rely on anyone in a world where every ally could become an enemy? And more importantly, what price will they pay to protect each other-and perhaps redeem themselves from a history that refuses to stay buried?

In this Story Osamu Dazai has a younger sister, her name with be Haruko Dazai. The events of this story may differ from the original anime with some of my OC (original characters) being added in.