Kikunosuke, alias Usaki, operates as a charismatic thief distinguished by his blond hair. He steals from the wealthy to aid the less fortunate, embodying chivalrous ideals. This role cements his leadership within the Kikugumi, a band he co-founds with the high-ranking courtesan Usugumo, Western medicine practitioner Aoto Touichirou, and Usugumo's pet cat, Kotetsu.

Drawing deliberate inspiration from kabuki tradition—specifically the character Bentenkozō Kikunosuke in "Shiranami Gonin Otoko" (The Five Thieves)—his narrative reimagines the original villain as a justice-driven altruist. He excels in deception and disguise, notably infiltrating targets by cross-dressing as a Shimabara courtesan to evade detection.

Within the Kikugumi, Kikunosuke acts as both protector and combatant, prioritizing Usugumo's safety. Her concealed identity as the Shogun's daughter and Yoshiwara status attract threats: political enemies plotting her elimination and aggressive pursuers like the Kaga clan heir. Alongside Aoto, he counters these dangers to secure her future.

Beyond OVA events, he confronts antagonists wielding "Eleki" technology—electrical gadgets and mechanized dolls—forcing his thief group into clashes against advanced opposition.