Not in Textbooks 4

Original title: 教科書にないッ！4

The fourth in a school romantic comedy that features a popular comic by Kazuto Okada starring Ayaka Morikawa and Ryouma Baba. One day, a love letter arrives under the Japanese language teacher, Tairaku Arihiko, at Otome High School. Around the same time, an incident occurred around the student, Aya Shirakaba, who was living with him...