Kazuma Shino stands as the designated heir to the Shinno family, stewards of a declining sex-based entertainment empire. To reverse their financial downturn, his father dispatches him for specialized training aimed at revitalizing their operations. This regimen demands immersive study of sexuality across diverse settings under one absolute restriction: he cannot ejaculate in the presence of women. Breaching this condition forfeits his inheritance and heir status.

His training thrusts him into provocatively charged scenarios with Japanese geishas, testing his restraint to the limit. A distinctive narrative twist personifies his penis as an anthropomorphic sea lion—a tenacious companion guiding him through these ordeals. Kazuma's journey centers on enduring extreme erotic trials while clinging to self-control, striving to uphold his familial duties and secure his future leadership. The ultimate success of his training, specifically whether he avoids disqualification, remains undetermined.