Sachikazu lives in Hoshikago city which holds a festival called Hoshiai (Meeting of the Stars) every Tanabata. One early summer day, he went with his childhood friend Tsuyuri to a small shrine on the rocky shore to make an offering of handmade sweets. There they met the strange round being Manjuu-sama. After being embraced by it, Tsuyuri’s face turned increasingly red and her breathing became heavier. He was about to help her, but was instead pushed down. It looked like she was sexually excited. She turned back to normal after he sprayed his semen on her. Then, a girl in a miko outfit, Hozumi, appeared before them and proclaimed that since Manjuu-sama had awakened, she will help make sure the “Hoshiai Ritual” is performed accordingly.
The only way to combat the sexual urges that are caused by Manjuu-sama’s mysterious ability is his semen! With his younger sister Rin and English transfer student Anastesia also dragged in, the festival of love has begun!