Minori Kotani, who joined the company as a new graduate and works as an office lady, was in a workplace romance with Atsushi-kun, who belongs to the sales department. However, recently, her boyfriend seems to be infatuated with "big-breasted pubs" almost every night, despite claiming it's for work-related entertainment. Minori, who had more complexes about her flat chest than anyone else, wanted to regain her confidence. One day after work, she decided to attend a slightly dubious "self-improvement seminar" in a room in a building near the station.