Based on the romance manga "Koiko no Mainichi " by George Akiyama, serialized in Weekly Manga Goraku.

In a story that flits between serious drama and comedic farce, Shinjuku gangster Sabu and his young wife Koiko try to live a normal life, despite the interferences of gang politics and criminal deals. After she saves his life, Sabu's gang-boss, Tominaga, falls in love with Koiko, and sends Sabu into increasingly more dangerous situations, hoping to cause his arrest, and thus obligate himself to "take care" of Koiko while Sabu is in prison.

(Source: Anime Mushi)