The Orchard of Stray Sheep

Summary pulled directly from Steam - Some text may only be applicable to Steam platform

A small, garden-like Academy stands alone on a secluded island.
Ichirou Yamada has been transferred there to work as a teacher.
He is put in charge of Casserole, a beautiful, young girl who entered the school at the same time.

A little Eden.
The days roll by at the Academy.
Days that are boring but full of happiness.
However, things are not what they seem at this "academy"...

Has Ichiro finally found the peaceful days he's always longed for, as well as that someone he wants to protect?
He is still trying to overcome the loss and regret of his past amidst the warmth and tranquility of these days.

"Stray Sheep."

All the while trapped by the words of the girl he lost so long ago.