Minami Kentarou works as a salaryman at SOBY Electronics, sharing an apartment with Haruo, a former study mate. He is engaged to Reiko, his boss's daughter, who regularly makes him wait for extended periods and criticizes his appearance before canceling plans. Kentarou is initially portrayed as passive within this relationship.

His life shifts upon meeting Momoko Morita, an aspiring actress who declares herself the future Japanese Marilyn Monroe. After Kentarou accidentally costs Momoko her part-time job, she proposes moving into his apartment to provide domestic and intimate services in exchange for housing and support. Despite Kentarou's reluctance and attempts to set boundaries, Momoko persists through emotional appeals and strategic deception, establishing a central conflict as he navigates cohabitation with her while engaged to Reiko.

Complications escalate when Momoko secures a job at SOBY. This professional proximity forces Kentarou to manage overlapping pressures from his fiancée, workplace dynamics, and Momoko's persistent presence. His development shows subtle progression toward assertiveness, confronting Reiko's dismissive behavior and attempting to set limits with Momoko.

Kentarou's background details remain minimal beyond his career and connection to Haruo. His relationship resolution stays ambiguous, concluding with a break from Reiko while maintaining an undefined commitment to Momoko. His journey focuses on navigating the comedic and emotional tensions between these contrasting relationships within the original OVA's timeframe.