Tokyo Tutor: Starting with My Ex-Girlfriend's Sister

Having lived a peaceful life in Japan for twenty years, Yamazaki Kazukaze takes a summer job as a tutor. To his surprise, his student turns out to be his ex-girlfriend's younger sister. This failed relationship occurred in high school, but fortunately, her family didn't know him. Because the tutoring fee offered by the aunt was too high, and his ex-girlfriend was studying abroad, Yamazaki Kazukaze plans to finish his summer course and leave her before she returns home. This decision throws his otherwise uneventful life into many unexpected turns.