University student Asahina Ren unexpectedly reunites with an old acquaintance on campus — his ex-girlfriend Kawaragi Yuzu from his time in Hokkaido. The two had mutually broken up when Ren moved away, and slowly begin to reconnect. Then, on Ren's birthday, another ex-girlfriend from his time in Fukuoka, Yabuki Mashiro, appears — having canceled her studies abroad just to see him, she declares she will be staying in his apartment. Driven by defiance, Yuzu moves in as well. Thus begins their strange three-way cohabitation. Between university, his part-time job, and daily life with the two girls, Ren's heart begins to waver as feelings from the past intertwine.