I sense mild yandere tendencies - and love it!

I like that title. With just those two words, you know what kind of action we'll be seeing, as in, cowgirl + swimsuits.
"One-sided love", though...I dunno, seems reciprocated to some degree to me. Either that, or he's just not stupid enough to look a gift horse in the mouth, or rather, a cute girl offering sex. 
That being said, she does give off the vibe of a rather possessive girl...And that's the first step on the road to becoming a yandere.

I wonder what could have happened to make him so worn out... :D

Yeah girl, bust that bronco!

Miu-chan's method of "treating a sprained ankle" is definitely a detriment to Kousuke-senpai's ability to perform well as a swimmer, as well as possibly a drain on his vitality. Not to mention her declaration (if only to herself at the end) ... I agree with GHOE; "Yandere Alert" currently set at "Yellow", with possible upgrade to "Red".

SCARY!