Mei Mei knew since she was born that she would not have a normal life, having as parents Chuuya Nakahara, one of the executives of the port mafia, and Osamu Dazai, a former executive of the port mafia. One would imagine that due to the influence of her parents' work, Mei Mei would be influenced to be part of the mafia, even if she was not part of the port mafia

Rumors have recently emerged in Yokohama about a new mafia operating in the city. As a means of espionage and to discover new information, both the port mafia and the armed detective agency, they decided that it would be better to place some of their members there as spies, and by chance or luck the chosen ones were Dazai and Chuuya

After several days trying to discover the location of the mafia headquarters where Mei Mei worked, the two infiltrated it. What started well soon went downhill when one came face to face with the other, which soon led to two arguing, even though they were already inside one of the offices of one of the mafia executives where Mei Mei was. They freeze and remain silent and in shock when the door opens, revealing the figure of none other than their own daughter.

Chuuya: Don't ruin everything you idiot He says softly just so Dazai can hear

Dazai: shhh I know what I'm doing, I'm not irresponsible he says before sitting on the chair in front of the table