Rin (Sho Hirano), Yuu (Hinako Sakurai), Koyomi (Tina Tamashiro) and Keita (Hayato Isomura) are friends at high school. They all live in the same apartment building. Rin and Yuu like each other, but they don't tell each other how they feel. To hide his feelings for Yuu, Rin often makes biting remarks to her. Yuu doesn't know that Rin likes her and she isn't confident enough to tell him her feelings. Kazuma (Kentaro Ito) then appears in front of them.