这份恋情有罪吗！？

母胎单身，情商为零，不知道自己为何而生的自卑处男工薪族·小日向大河（24岁）在上班途中因为某个“小事故”第一次坠入爱河。 他爱上了童颜巨乳的大姐姐·驹田多惠（32岁）。而治愈系的多惠的真实身份居然是一位职业女棋手！？ 不在同一世界的自卑处男和美女棋手的姐弟恋就此展开……这份恋情，有罪吗Tae Komada is 32 years old, well endowed as a woman and a Shogi chess player. She looks much younger than her age. However, she has neither love experience nor communication skills. Meanwhile, Taiga Kohinata is a 24-year-old salaryman and is still a virgin. Taiga happens to meet Tae and falls in love with her.