Yuki was responsible for tutoring 3 college kids. Ryo, Ri and Koji were regular college students, going to parties, playing their video games. But the studying suddenly began... These kids tie Yuki with ropes and shut her mouth with a ball gag. Yuki, who was to tutor these young kids, were forced to unwillingly give her freedom up as they peered deeper and deeper within here! In addition, these kids who were so eager to "study" and brought out their own "toys" and started teasing her body. Then next came their own... Yuki violently resisted as her face flushed a bright red. However, her body mercilessly falls under control of these kids her body discovers these new pleasures.

What are stock anime characteristics you dislike?

It is strange that nobody mentioned that (and concentrated on boobs instead), but I seriously dislike “let’s torture a character to trigger sympathy” sequences, especially when coupled with a “jester” villain. There’s an incorrect scriptwriting idea that if you throw a lot of horrible stuff on some character (preferably main protagonist) or put them through horrific events, they’ll somehow will become more likeable.
Basically, Break the Cutie and Kill the Cutie tropes, maybe coupled with Diabolus ex Machina - TV Tropes . Some offenders: Re:Creators (dropped it), Juuni Kokuki , RE: Zero kara, Saber Marionettes (J? I think), Taimadou Gakuen 35 Shiken Shoutai Basically… it is that thing where in order to attempt to trigger sympathy towards character, scriptwriter decides to throw everything the world has at that character.
Everything said character holds dear will be destroyed, set on fire, brutally killed or worse… and most likely this will happen while the character is watching and can’t do anything.
Those kind of story arcs often drag out for several episodes, and essentially are a poor scriptwriting.
Juuni Kokuki actually went as far as attempting to rationalize that this is somehow character’s fault.
Sigh. Extra annoying when coupled with a “jester villain”.
A recent example: A “jester” usually appears out of the blue, proceeds verbally or non-verbally torturing the most vulnerable character of the cast (while a dozen of perfectly armed people let him/her finish instead of turning the “jester” into mincemat), and promptly run away… unhurt. Just… WHY? The next annoying thing is “spineless shy awkward bespectacled otaku protagonist with no personality”, but those are slowly going extinct, and do not annoy me as much as “let’s torture a character for sympathy” thing. There’s a place for a tragedy and horrible events, but those events should be handled with care, otherwise they’ll end up cringeworthy.