Mahiro-chan (over a year of middle school experience) has brought classmate boys to his room and suddenly started undressing

A former adult man who doesn't realize he's been saved by YuuMina's tact and purity

Actually doesn't realize it

Formerly of the same sex, now of different sex, TS girl who's not aware how charming her appearance is and how many misunderstandings her words and actions have caused. The boys' bane.

Perfectly unaware

Taking her shirt off in front of them...

Coincidentally, if something happens, Mahiro-chan will be the one in legal trouble.

Seduction of two underage boys, commonly known as "OyaFault".

"O, Oyama's...! Is this an opportunity!? Is this the kind of development we saw in reference materials!? With the three of us!?" "...No, no way! Oyama-san is popular, and she probably wouldn't even consider us! She'll hate us if we just try to push her down, it's better to get out!" They may or may not have this kind of rapid-fire mutual understanding.