No, It's not written in the rule but if he do that there're a 100% chance that that person will confess back and he'll die? Or it might become a loophole.
In summary, he'll die if:
SO confesses to him that truely love him romanticly. Joke might be safe?. So far only Ayano truely love him.
SO...
The things is he can't reject or do anything that lower ones affection toward him once he know the person loves him either. If he do, he'll get a very terrible headache or even dealth. (Chap 6, pg6)
His can only try to avoid the situation and not to build a harem until graduate.
It did have a BL tag. Briefly. For a week or so.
I remember when the BL tag was updated, I was like "I knew it...". Then a week later, it was gone and left me confused to this day 🫠