The plot quickly escalates from a typical romantic comedy setup into a more explicit and psychologically complex territory. Akira, who initially sees his sister as an annoying obstacle, begins to realize that the traits he admires in his classmate are eerily similar to those of Rio. This realization triggers a profound and unexpected turn in his life, as his feelings for his sister develop into a physical and emotional relationship, leading him to question the very nature of his first love and the boundaries of a sibling bond.
A calm, shy middle schooler who is frequently flustered and embarrassed by Ichika's intense actions.
The protagonist discovers that his long-time first love is actually set to become his stepsister due to a parental remarriage.
For decades, manga and anime have used the "forgotten childhood friend" trope. The protagonist never remembers the promise he made to the girl in the past. The "Verified" movement rejects this. It demands . The protagonist must remember that his first love was his sister-like figure. The tragedy or romance only works if the verification is conscious.