Throughout the games, she befriends other young men whose personalities are based on the Western zodiac constellations.
In the first game, Starry☆Sky~in Spring~
, not long after Tsukiko transferred to Seigatsu Academy, a half-French boy named Yoh Tomoe follows the suit to pursue her. This action stirs up emotions from Kanata and Suzuya, both of whom had long loved Tsukiko.
In the second game, Starry☆Sky~in Summer~
, Tsukiko has joined the academy's archery club. As she practices for the summer competition, she also solves the problems between her teammates (Homare Kanakubo, Ryunosuke Miyaji, and Azusa Kinose) simultaneously.
In the third game, Starry☆Sky~in Autumn~
, Tsukiko becomes involved with three teachers at her school, who are Iku Mizushima, Naoshi Haruki, and Kotarou Hoshizuki.