Naoto Watari has had his share of struggles: his parents died two years ago, and now he and his sister live at his aunt’s house. There, his desire to protect his sister earned him notoriety as “the guy with the sister complex”—which never mattered to him, as his sister always came first. But when Satsuki, a childhood friend-turned-enemy(?), becomes his school mate, Naoto’s ordinary life is thrown into chaos … and Satsuki may just be the beginning.
Naoto went with his classmates to the beach on a trip arranged by his friend. His goal was to get closer to Ishihara-san, the girl who is universally adored by his classmates. Shortly after arriving at the inn, Naoto and Ishihara-san went to get some lunch, and they had a good time together. However, everything changed when a man rumored to be Ishihara-san’s ex-boyfriend showed up! The relationships between Naoto, Ishihara-san, and Satsuki have started to crumble apart. Naoto’s everyday life just won’t be the same after this trip!