The hentai is based on the visual novel of the same name by Rune Soft studio in 2004.

The protagonist of the hentai is an ordinary Japanese boy who has been living an ordinary carefree student life. Everything changed in the spring after his best friend and his beloved officially announced their relationship to everyone. The protagonist never thought about finding a soul mate, and now that his friend suddenly became more mature, he thought about it and realized his loneliness. After a while, the protagonist's little sister invited the poor guy to a tennis match, where he met a wonderful girl who could potentially become his chosen one...