his mother abandoning him. That causes problems with other relationships in his life especially with the female lead who he thinks will abandon him as well because of the second male lead who also likes her. In the end though, the male and female lead get together. Maybe his mother comes back at some point or is a prominent character, but he hates his mother and doesn't forgive her.

The first thing that comes to mind is Gomen, Aishiteru

Madame Antoine, but I'm afraid I don't remember how things ended with the mum. 

I feel like I've seen this theme in many shows, but most (all ?) of them have the son and mother reconciling in the end. 

Pride --- exactly what u describe, abandonment issues, causes problems w/ FL, afraid she'll leave him for 2nd lead, mother comes back at one point.    He does Not reconcile exactly ...  perhaps  he forgives, but he certainly does let go of the past and her.

 Linus:

I feel like I've seen this theme in many shows, but most (all ?) of them have the son and mother reconciling in the end. 

Yeah and sometimes it's understandable, but then other times annoys the shit out of me because the mother doesn't deserve it.

Are you looking for a certain drama or any recommendation with similar plot? 

I would reccomend MARS - the main lead was abandon by not only his mother, but also by his brother and father and he has mental issues because of that. 

✔️ High School Love On  

✔️ Scarlet Heart Ryeo

✔️Gu Family Book

 Stevie70:

✔️ High School Love On  

✔️ Scarlet Heart Ryeo

✔️Gu Family Book

Scarlet Heart does have severe abandonment issues, but it's a bit tricky. I'm not sure if I would put it on the list considering the ending.

You have me thinking now. I watched a drama that was exactly like what you want but I can't remember what it was. I keep thinking it's the Thai - You're my destiny., But without watching it again I can't be sure