takes place in a darker version of Yokohama where Osamu Dazai became the young boss of the Port Mafia instead of leaving it, ruling the city from the shadows alongside his partner Chuuya Nakahara, one of the organization’s strongest executives. Away from the criminal underworld, they secretly raise two children at an elite private academy: their oldest child, who inherited Dazai’s brown wavy hair, intelligence, and unsettling presence, and Ren, their loud and sarcastic younger son who acts more like a normal American teenager despite living in Japan. Neither sibling fully understands what their parents truly do, only noticing the black cars, dangerous adults, and strange fear people have around their family. Meanwhile, Yokohama grows increasingly unstable as figures like Atsushi Nakajima, the feared White Reaper of the Port Mafia, and Ryunosuke Akutagawa of the Armed Detective Agency become tangled in conflicts connected to Dazai’s plans, forcing the siblings closer and closer to the dark truth surrounding their family.