The main character, Ryoma Tsukahara, is now 10 years old. He is a boy who regularly goes to a martial arts dojo to train his body and his "manly ways." Ryoma's family is quite unusual. A father who refuses to go to work and hates his work, and a mother who is naive and spoiled. And his younger sister, Shizuka, is a reliable person who takes care of all the housework in place of his parents. In place of his father, Ryoma decides to support the family. He starts working at the top-class general trading company, Giant Shoji, where his father works, but...!?