The first chapter of the Refrain Blue series, tells about the recollection of Yoshihiro's past about various events of summer school, of the fate where encounter and separation are interwoven with each other, as Yoshiro and Matsunaga will pass the Toyo Gakuen and will arrive at summer school at seashore. A mysterious girl smiles as she watches Yoshiro who stands still at the seashore dusk.
| Actor | Role |
|---|---|
 Katsuyuki KonishiYoshihiro Matsunaga (voice) | Yoshihiro Matsunaga (voice) |
| YYumi KikuchiNao Morisawa (voice) | Nao Morisawa (voice) |
 Shizuka IshikawaChinatsu Iwasaki (voice) | Chinatsu Iwasaki (voice) |
 Mari AdachiTsugumi Tsugashima (voice) | Tsugumi Tsugashima (voice) |
 Ruri AsanoYuori Kawana (voice) | Yuori Kawana (voice) |
 Mie SonozakiMikage / Mysterious Girl (voice) | Mikage / Mysterious Girl (voice) |
 Ai UchikawaShizuka Hayase (voice) | Shizuka Hayase (voice) |
 Daisuke KishioRyouji Itou (voice) | Ryouji Itou (voice) |