Eh... It can totally be read as a comedy. For myself, at least, I didn't take it seriously but as an exaggerated parody of yandere-yuri romance, and it parsed just fine as that (though falling into the pitfall where romcom parodies tend to become what they are parodying to some extent)
—for instance the odd "ah yes I can feel the sincerity of her heavy love... wait, WHAT tracking devices?" sort of moment at the end, felt more like classic Japanese joke pacing to me than anything else. And so many jokes around the protagonist's absurd lack of perspective, like, "I only sent 80 messages, I've been very reserved!". Whilst others are one-offs like the grandma getting shoved off the roof by, what, "yandere poltergeist powers"?
I am not claiming the humour was all especially funny or in good taste, it should be said. Just that I think it was... intended? XD
The notion that it needs no other tags is also dumb, though. The humour here is way too dark for that. Adding a "psychological" tag, since that seems to be traditional for "yikes, but this yandere is creepy."
This is... Cool? I'm not sure heavy is the right translation but damn. It's too silly to be psychological but it makes more sense than any other tag I guess...