The plot centers on Tsubasa Sonokawa, a fifteen‑year‑old high school student who becomes enamored with an upperclassman after he rescues her from fainting at a train stop due to anemia. She interprets the encounter as destiny and pays him visits in his classroom daily. Yet he declares her emotions to be "heavy" and ends the relationship. Later, while assuming her friend Yuri"s role as manager of a boys" basketball squad, she meets another boy. She discovers that her bond with this new guy, Aki, may be deeper than she initially imagined in the unfolding chapters of her evolving heart.
