Nibiiro no Hako no Naka de

Miwa, Motoaki, Ritsu, Aoi, and Satoru have lived at the same apartment complex for years and they are childhood friends. When they were younger, they always played together. Now, they are high school students and they attend the same high school. They are still friends, but their relationships have changed.

Miwa has feelings for Motoaki, but she can't tell him about her feelings. Motoaki is unaware of her feelings towards him and treats her like a friend. Aoi acts like she is good friends with Miwa, but, Aoi is frustrated by her sense of inferiority and jealousy towards Miwa. Aoi is dating Satoru. Meanwhile, Ritsu complains about the relationships of the other 4 and keeps his distance from them.

(Source: AsianWiki)