This is part of the Arai Yuuko Masterpiece Collection.

Other volumes in the series:
1: Cola de Kanpai!
2: Futari no Tabidachi
3: Mawari Michi Hitotsu
4: Yuuyake Iro no Rakugaki Note
5: Umi wa Mou Haru na no sa
6: Mayonaka no Niji