I want to start this by saying that "friends to lovers", and childhood friends are some of my favorite tags. A great example of this kind of story is an anime that aired recently "Tomo-chan is a girl". Tomo-chan has everything I want out of a childhood friend to lovers story. The characters have a lot of history, that reflects in their interactions. They clearly care about each other, and fear that taking the relationship further might endanger the friendship they have now. These sort of conflicting emotions, and the growth the characters need to raise above it are the staple of this genre.
Just don't expect to find it here, in "My Childhood Friend Attacked Me When I Declared That Her Birthday Present Was 'Me'". These characters are not endearing at all, none of them. The MC could be considered "weak willed", going with the flow but wining about it for 12 chapters strait. Personally, I feel sorry for him.
Spoiler
although it was written ambiguously (the s*x scene happens offscreen), you can interpret it as him being r*ped by the childhood friend. All we know for sure is that it was done multiple times, and without cond*ms/contraception.
The FL is really bad, a single joke was enough for her to pounce on him, and force them to be in a relationship he didn't want afterwords.
Spoiler
Gaslighting him, and making him take "responsibility" for possibly imp**gnating her. All the the parents are just as bad, driving him into a corer to not let him escape.
I was honestly a bit disgusted, why write it this way? This has the "Romance tag", its supposed to be romantic! I can hardly think of anything less romantic than this.
If you are feeling in the mood for a nice childhood friend to lovers story, I suggest you give this one a hard pass. I think you can find plenty of other, better novels to read than this one.