Sister Rio, are you coming to watch the sports festival?

After finishing his first high school exam, Haruto Arisawa reminisces about his date with Rio Misumi and coincidentally reunites with his elementary school friend Ichika Yukinari at the upcoming sports festival executive committee meeting.
While reminiscing about those days and chatting, Haruto reveals to Ichika, who has feelings for Haruto, that Rio is the one he likes, in response to his friend's comment that she would be happy if Rio came to the sports festival.
Likewise, Rio, who wanted to see Haruto perform at the sports festival, visits his alma mater at the invitation of Nao Misumi.
However, on the day of the sports festival, seeing him enjoying his high school life and Ichika next to him, she hesitates, wondering if she should push Haruto away, as she doesn't want to disturb him...