Shy high school student Makoto Ito glimpses Kotonoha on the train; too shy to talk to her, he snaps a photo of her; when Sekai Saionji, his new desk partner, sees the picture on his phone, she offers to play match-maker.

After building up the nerve to ask, Makoto takes Kotonoha on an awkward first date; after a failed attempt at a kiss, Sekai coaches Makoto the next day.

After Kotonoha and Makoto spend an afternoon with Kokoro, Kotonoha's little sister, Kotonoha reveals that she would like for them to call each other by their first names.

Makoto and Kotonoha make out on the roof, but it's cut short when he tries to get to second base.

Makoto and Kotonoha go to a water park with Sekai and friends, and everyone except Makoto seems to have a good time.

After their illicit night together, Makoto and Sekai start seeing each other; it doesn't take long before she starts feeling remorseful and urges Makoto to reveal their affair.