I think this is the first version of this trope I've seen where the crossdressing boy is still kind of a horndog. They're usually all-in with the purity cliche, but this one's just a dummy in puberty. That was a really cute story!
Dude didn't even disengage the safety on that AK. Poor form on his part.
I mean, seeing how they were actually the replacement bodyguards acting on Tohru's behalf, of course they'd make sure no one gets accidentally hurt. :P