Uzaki in a one-piece swimsuit = high speed, low drag SUGOI DEKAI 🤤
My theory on her current pestering is that she made subtle, indirect indications of her affections, which Sakurai misinterpreted, being an introvert who never learned coygirlese:
(example)
Uzaki: "Senpai, sure is a nice day outside, huh?" [Translation: We should go on a picnic/date together.]
Sakurai: "Yeah, it is." [Translation: Confirmation that the weather is indeed nice.]
Eventually all that bottled frustration at him not getting it and it being socially faux pas to confess directly led her to blow off steam by teasing him. Which she found she really enjoyed, due to lingering immaturity.
P.S. Hana-chan, just confess already and save us a few volumes please.