She guessed that Hana initiated the kiss with Kiyoshi
because she already has an inkling that Hana is crushing on Kiyoshi.
Now, I think she is rejecting Kiyoshi because she has realized
he is subconsciously more into Hana. Notice how her one question,
her one test for Kiyoshi, was whether or not he kept Hana's panties.
He failed that test, so she will turn him down to avoid getting
mixed up with a guy who is really into another girl.
