Masa, a former yakuza underling from Tatsu’s disbanded gang, navigates post-crime life with disheveled charm—light blonde hair wild above brown eyes, injuries hidden under bandages, and an open shirt revealing a white undershirt. Pierced ears and a neck chain underscore his rough-edged aesthetic. Clinging to faded yakuza pride, he flounders in mundane society, cycling through short-lived jobs and cluttered apartments while resisting change.

His dynamic with retired boss Tatsu shifts unpredictably from domestic comedy to reluctant mentorship, as Tatsu drags him into chores or repairs. Though initially lazy and inept at housekeeping, Masa gradually adopts tidier habits through exposure to Tatsu’s disciplined domesticity, waking early or scrubbing floors—yet misapplies yakuza bravado to household tasks, sparking clashes with rival gangs or reliance on Tatsu’s protection.

In the live-action iteration, Masaru Akamiya ("red shrine") battles lingering tensions with the Kunimi Clan and a dental phobia. He addresses Miku with informal reverence as "Boss Lady," while his one-sided camaraderie with Tatsu—who often forgets their shared past—fuels deadpan humor. Poor English skills and a penchant for misreading situations through a gangster lens amplify his comedic mishaps, contrasting his ironically elegant name with a clumsy, trouble-magnet persona.

Later narratives trace his halting growth toward responsibility, balancing impulsive flaws with earnest efforts to mirror Tatsu’s guidance, even as old habits die hard.