Rika Mikuni's parents divorced when she was very young.
Her father took her in and raised her without any difficulties, but she cannot easily forget her mother.
Then she hears that her mother has remarried and decides to visit her while her father is away on a business trip.

In the town where her mother lives, Rika meets a boy named Minamoto Seiya.
At first, Rika is surprised by the popular and very forceful Seiya.
However, she finds herself liking Seiya, who laughs a lot and expresses his feelings to her in a straightforward manner.
But, to her surprise, he is the son of her mother's second marriage!
The two are torn between "siblings" and "likes," and the future of their romance is ......?

(google translated)