As children, the twins Yanbo and Mabo bullied Kenji and his friends. Their weight and strength gave them an edge. The only person who could defeat them was Yukiji, and they harbored a grudge against her for that. When they ganged up on her, Kenji intervened to protect her but ended up getting beaten by the twins. Later, Yanbo and Mabo destroyed Kenji and his friends' base in retaliation.
Much later, it is revealed that Mabo and Yanbo are now heads of a large business office, having transformed into compassionate and kind individuals towards their employees. They seem to have forgotten the terror they once inflicted upon Kenji's friends, as Yoshitsune inquired about it. They claim that they were merely trying to "become friends" with Kenji's group. It is then revealed that the two twins are devoted followers of Friend.










