Enoshima Abyss

A certain app was installed on the smartphone of Yuukei Nagino, a high school student who had given up on having a proper youth. The app was called “Youth Matching App.” It rewards you for completing missions designed to help you experience a “proper youth” with your matched partner. And his match turned out to be none other than Hana Hanamiya, the beautiful girl from his own class. She wants to complete the missions in order to make her own dream come true. To discover what youth really means, and to make Hana’s dream come true, Yūkei carries out the missions sent to him—but… A youth school romantic comedy that begins with a mysterious app!

On his very first day of starting high school, Namito Kominato's homeroom teacher has him sit behind a strange girl who wears a paper bag over her head and is always soaking wet with sweat. Her name is Samidare Kamiyama, a extremely shy girl with severe social anxiety. Ultimately, she meets Hinata Arai (the student council president who's kind and helpful, but alarmingly obsessed with her uniform) and Harusame Amano (a girl who only speaks to a cardboard cutout of a magical girl).Alt official source