Did you read this explanation and think "what a useless waste of time?"
Are you one of those people who are virtually certain you have read 500 other manga just like this, and are concerned that this title is complete shit?
In either case, you are correct!
No plot except "big-tiddy girl likes boy" with an MC who has literal negative values of self-esteem who insists upon being treated like a doormat in any and all circumstances; he demands that others mistreat him to prove his lack of self-worth is justified, in fact!
Unless you have a very specific kink, this novel is not for you.
(And, if you do have that very specific kink, well.... I'm not going to kink-shame you, but I would like for a lot of people to maybe keep these kind of anti-self-worth kinks behind the bedroom door, please?)