During her elementary school years, Sayaka Saeki took great pride in being the ideal student—excelling in academics, taking part in club activities, and always presenting herself with perfect decorum, confident that her life was unfolding exactly as intended. That certainty was shattered when a teammate from the swimming club confessed her feelings to Sayaka, forcing her to realize that emotions could upend even the most orderly and rational existence.
Entering middle school, Sayaka chose to cooperate with her classmates instead of competing with them, and she grew close to an older student named Chie Yuzuki. As their friendship deepened, Yuzuki eventually confessed her love to Sayaka. Hoping to understand the nature of love, Sayaka returned those feelings, but despite neglecting her studies for the relationship, it ultimately ended, leaving her wounded and bitter.
Resolved never to let her emotions control her life again, Sayaka swore to reclaim her independence once she started high school. But when she meets class president Touko Nanami, she finds herself forced to confront the conflict between staying true to who she is and preserving her logical, detached approach to life.