Ayuha Samaru may be airheaded, but she is straightforward in her pursuit of love. Unfortunately, her attempts have always ended in failure, even after confessing seven times. Frustrated and hopeless, Samaru's friends try to comfort her, but their happiness in their own relationships only adds to her misery. However, everything changes when she meets her substitute homeroom teacher, Yoshitaka Hiromitsu. Despite his blunt honesty, she finds his advice and kindness refreshing, and soon falls for him. But is it true love or just a passing fancy? Sensei Kunshu follows Samaru as she tries to win the heart of her teasing teacher, with additional one-shots included in the volumes.