Masa is a member of Tatsu's old yakuza gang. They've struggled to deal with the Kunimi Clan since Tatsu left their gang to become a full-fledged house husband. After meeting Tatsu by chance and getting dragged along on his chore routine, Masa learns the hard way that Tatsu is still adamant.

Masa has a bad habit of getting himself into trouble which is reflected in his bandaged appearance. Masa is also very lazy. It is also seen that Masa struggles to hold down a job.