15-nenme

Chisato and Reiko have been childhood friends for 15 years. They have different hobbies and personalities, but they have fallen in love with the same boy ― Keisuke Sugimoto, a member of the same music club as Chisato. When Keisuke confessed his feelings for Chisato, she was more concerned for Reiko―.

(Source: Shueisha, translated)

Collected Stories:
1. 15 Nen Me (15年目)
2. Ano Natsu (あの夏)
3. Garasu no Houseki (ガラスの宝石)
4. Yuki no Hi Kara Hajimaru (雪の日からはじまる)