'Offensively cliche' sums this up pretty well.
The "heroine" is almost entirely flat beyond a conflict of "it's bad for girls to be strong, but she likes karate" which the writing doesn't manage to pull off in any interesting way or even be entirely convincing that the author doesn't share those views. The lust interest is a childhood friend that became distant from the "heroine" due to a misunderstanding, but manages to make her his "toy" because of exploiting a loophole in a bet they made where all she wanted was to figgure out what caused the rift between them. Then we get some attempts at eroticising what is at least borderline sexual abuse.
Do the characters have any real chemistry? not a bit, so the romance just falls flat
Are there any hints in the first 8 chapters that she actually has a hidden submissive side and likes it? No, she just lets the first bishonen strong enough to "take her" do what he wants just because he keeps reminding her she'd break her promice if she stopped him. (and she even goes back to him after she gets freed from her promice...because she likes his body I guess)
Does this trait of being honorable to a fault show throughout her life as a core part of her identity? No, it's just an obvious plot device to get into her pants/skirt.
Is the love interest that breaks her free of her promice to the abusive male lead really distinctive from him beyond having slightly less problematic boundry issues? Not beyond having a slightly lighter shade of hair (to the point where you can confuse who's in the pannel if you're not paying close attention, because they look and act so similar)
Do they at least start developing these characters properly after that arc is done? Nope, moving right into an abusive teacher trying to destroy their "relationship" to get into the lust interest's pants.
Does she at least make for a menacing villian? No, because she's even flatter than the main characters who we don't have any real reason to care what happens to even by the time she's introduced, and since it's obvious she's just being setup as a blantent antagonist to just get removed in a few chapters, we can't even believe she's a credible threat to a relationship we don't care about.
Do they at least make it titilating? No, it even fails at being mere smut.
Artistically, the character designs are alright, but between the lack of variety between characters or consistancy and generic designs overall, I can't give high marks there either. Unfortunately the backgrounds, when there are any, are entirely bland and unimpressive, and most of the time, space is just filled with white, black, or seemingly random visuals, so one can't even say the enviroments or other visuals are where the artist shines. It's not bad enough to be visually offensive, so it does outdo the actual writing and characters of the manga, but it doesn't actually bring anything notable to the table, and its flaws hold it back from being entirely unnotable.
Just go read something like Maid Sama which is basically just what this manga wishes it was (and even has an anime series), something else from the recommended tab, or just some actually titilating smut if you want something more sexually explicit.
Please note:
I don't give 1-star reviews lightly. This manga has earned the mere 3rd 1-star rating I've ever given out of 232 ratings I've made on this site to date. I reserve that distinction for stories that not only bring nothing of value to their audience, but find their own special way of being actively terrible. So, when I ask you to treat this as the 'Twilight' of manga, please understand the weight I'm putting behind those words.