The first of the four Starry Sky games starring the characters from the drama CD's of the same name. Starry Sky takes place at Seigatsu Gakuen, a school which specializes in horoscopes, astronomy and other related topics. The main characters are all based on horoscopes. Starry Sky Spring features Suzuya Tohzuki (Cancer), Kanata Nanami (Pisces) and Yoh Tomoe (Capricorn). It follows main character Tsukiko Yahisa, who's the first girl to enroll in the school, and her first semester there, which she spends with her childhood friends Suzuya and Kanata along with Yoh, a transfer student who came from France.

Tsukiko Yahisa is the first female student to enroll at Seigetsu Academy, a former all-boys school specializing in astronomy. She is closely watched over by her childhood friends, Kanata Nanami and Suzuya Tohzuki, who often protect her from the male student body. Throughout the games, she befriends other young men whose personalities are based on the Western zodiac constellations.