Traumatized by a childhood incident with a friend who took exception to his love of traditional dolls, doll-artisan hopeful Wakana Gojou passes his days as a loner, finding solace in the home ec room at his high school. To Wakana, people like beautiful Marin Kitagawa, a trendy girl who's always surrounded by a throng of friends, is practically an alien from another world. But when cheerful Marin—never one to be shy—spots Wakana sewing away one day after school, she barges in with the aim of roping her quiet classmate into her secret hobby: cosplay! Will Wakana's wounded heart be able to handle the invasion from this sexy alien?!

High schooler Hayase Nagatoro loves to spend her free time doing one thing, and that is to bully her Senpai! After Nagatoro and her friends stumble upon the aspiring artist's drawings, they find enjoyment in mercilessly bullying the timid Senpai. Nagatoro resolves to continue her cruel game and visits him daily so that she can force Senpai into doing whatever interests her at the time, especially if it makes him uncomfortable. Slightly aroused by and somewhat fearful of Nagatoro, Senpai is constantly roped into her antics as his interests, hobbies, appearance, and even personality are used against him as she entertains herself at his expense. As time goes on, Senpai realizes that he doesn't dislike Nagatoro's presence, and the two of them develop an uneasy friendship as one patiently puts up with the antics of the other.

Time flies by; Hiroyuki and Akari are 12th-graders now. Both of them and their friends have grown up gradually in someway, physically or mentally, but one of their best friends is missing: the lifelike android Multi. To their surprise, Multi is brought to their campus again without notice, yet she is no longer the same Multi they have known.

Okano Makoto transferred to the school in his home town. There, he spent normal but happy school days with his sister, Hinata, a jokey classmate, Tachibana Tsutomu, Shikouin Kasumi, Tsutomu's childhood friend, and other friends. One day, after school, Makoto heard someone playing the harmonica. That melody made him feel something old, and it brought him to the roof of the school buildings. There, he met a girl in the dusk. It was Narukaze Minamo who turned her face to him with a smile. She was a childhood friend, but they had lived separately for years. Hiding their true thoughts, Makoto and his friends spend their lives in school. Their stories in a mysterious town are about to begin.