Mysterious Girlfriend X/YMMV
- And the Fandom Rejoiced: When a TV series was announced.
- Arc Fatigue: The Idol storyline went on for longer than some people liked (a year in real time) before the arc finally came to an end in chapter 48.
- Audience-Alienating Premise: To those who are bothered by saliva drinking, or to those who simply have trouble swallowing the premise.
- Broken Base: The Idol arc. Not only did it take an extremely long time to resolve, but for many it also marked a change in Urabe's personality, causing her to ignore her increasing feelings towards Tsubaki and become increasingly hostile to his attempts to simply make physical contact with her.
- Fetish Fuel: This manga runs on Fetish Fuel. A short list: glasses, spit/drool, finger-sucking, stoicism, weird tan lines, bikinis, short girls...
- Plus short hair (the protagonist's personal turn-on), exhibitionism, school swimsuits and more than a little Les Yay.
- ...ear licking, hair play, panty shots, possessiveness, body paint...
- Imai Momoka wears some easily visible restraining garters.
- ...cutting off a girl's clothes, upskirt, downblouse...
- We have eating raw bacon while wearing cat ears. ...Wait, what?
- Everything's Better With Bacon!
- which furthered into a hinting of a Catgirl fetish.
- Face masks, fevers... when did this turn into Ai Kora?
- Genius Bonus: The covers of the books contain rather large portions of the English language versions of various literary classics -- the original Frankenstein for Volume 1, for example.
- Les Yay: Urabe and Oka, exchanging saliva whenever they have lunch (not like that! Granted, it's kinda kinky all on its own...).
- Oka peeking down Urabe's top.
- Magnificent Bastard: Akira's ex-crush, Hayakawa. To the point that she's openly taunting Urabe, faking being in an abusive relationship, and suckering Akira into faking a date with her -- at the same time she's getting Urabe to show up to "accidentally" catch them so he'll take the fall for it. Turns out Urabe was one step ahead of her...
- Moral Dissonance: Urabe shreda Tsubaki's magazines simply because she disapproves of them. There's also the case of the public property she desecrates by cutting it to pieces...
- Squick: Sucking saliva off someone's fingers may not be the most romantic thing for most people.
- In the anime it's drawn a lot thicker and gooier than it looks in the manga, with a slight yellow tint.
- What an Idiot!: Tsubaki, multiple times. Part of it is due to his naïveté, part because he has had the Idiot Ball surgically implanted and partly because his girlfriend is, quite honestly, really weird.