When Izumi Norimoto and Kazusa Onodera were young, they were the best of friends, inseparable as if they were siblings, enjoying each other's company with laughter and play. However, as they began attending middle school, Kazusa began to see Izumi in a different light, and so did the other girls. Consequently, Kazusa was shunned, leaving her with no choice but to distance herself from her childhood friend. After joining the literature club in high school, Kazusa found comfort in the company of her new friends, notorious for reading steamy sections from literature novels. The club's notoriety, however, made it difficult for them to find a teacher to advise them. During a discussion on their aspirations, the mention of sex by one of the girls sparked newfound curiosity in the group, and they became fixated on the idea. One day, while accidentally walking in on Izumi in a private moment, Kazusa was forced to confront her true feelings for him. With their hearts racing and the threat of the club's dissolution looming, the five girls must fight to hold onto their club and their sanity.