An evening of the spring vacation.
Mitsuki who is temperamental girl is entrusted with a "goose" from her father.
"Goose" was Taiki which is Mitsuki's fiance who quit a school now and is acting as an adventurer together with his father which did not have communication for eight years!
When the night comes, Taiki has come to become a goose by curse of a ghost.
With a strange mystery and a bittersweet memory, every day of Mitsuki and Taiki begins, but...?