Mikey is the head of the main criminal gang in Japan. He had no one left, but at one point he found out that his best friend Draken, who has been dead for a long time, has a younger sister. Azumi Ryuguji is 16 years old, he wanted to meet her and find out who she is This and another reason she was an ideal version of Draken but female

And then he knocks on her door and she opens it Hello, are you Azumi Ryuguji?