Houkago no Ban'yuu Inryoku

A place where the sky never changes, nor the town, nor the people...

One would think that Nanahiko lived an ordinary life.
She went to school and came home. Days passed unremarkably.
Then her somewhat estranged friend Kotori said:

"Would you fill in for me at work?"

A request is made. A mystery unfolds.
She meets a boy, and a certain truth is revealed.

[From DLsite English]