Sabu, a young Menso yakuza member, navigates the precarious balance between his six-month marriage to Koiko and his duties within the gang. Residing in a modest walk-up apartment, he enforces gang interests through calculated intimidation and physical confrontations, favoring non-lethal methods and pragmatic resolutions to avoid unnecessary bloodshed.

When superior Hoshinaga entrusts him with a firearm, Sabu delegates its custody to impulsive subordinate Matsu, unwittingly sparking reckless violence against the rival Tengenji faction. Sabu intervenes swiftly, defusing tensions without casualties and reaffirming loyalty to his allies through strategic restraint.

Koiko remains his emotional anchor, though he conceals the brutality of his world from her. Her inadvertent entanglement with the Menso boss—whose infatuation blooms after she assists him—forces Sabu to shield her from escalating dangers within his own ranks. Suspicions arise when Hoshinaga’s ambiguous behavior toward Koiko hints at hidden agendas, yet Sabu’s willingness to reassess alliances leads him to acknowledge Hoshinaga’s underlying honor, tempering distrust with evidence.

As a mentor, Sabu guides Matsu through the subordinate’s personal turmoil and rash choices, tempering discipline with patience. Amid rising gang conflicts, he strains to uphold yakuza obligations while protecting his marriage, striving to sustain stability through loyalty and adaptability even as external threats blur the line between husband and enforcer.