1. im searching for a drama that have a awkward or antisocial, or nerd guy as a main character, then he meet a girl and fall in love with her, for example Densha Otoko and Blindly in Love,

2. Harem drama like Moteki.

thank you :)

I mostly just watch Korean drama's, and the only one I can think of right now is Good Doctor. I love that drama. Oh and the movie Almost Love. Now that I think about it I wish there were kdramas with that kind of plot.
Good Doctor seems great and it have a good rating too, thank you very much for your recommendation :D
Ho Gu's love maybe :)
You're welcome! Glad I was able to help ^^
You can try K-movie The Plan Man (anti-social/nerdy/awkward guy meets girl) it's a rom-com. Pretty good movie imo.

Loved Densha Otoko!
If you are branching outside of Jdorama, Hi My Sweetheart is awkard falling in love
Don't know that much about J-doramas (sorry!) but first thing that came to my mind was a Taiwanese film entitled "Campus Confidential" and I also second "Hi My Sweetheart"
Date - the guy is a otaku + hikikomori
kdrama He who can't marry, the male lead was weird/awkward and had loads of issues and always said the wrong thing around the woman he liked. It's older cast though mid-late 30s. Very funny I would watch again
adding to HappySqueak's recommendation,that kdrama is actually a remake of a japanese drama,kekkon dekinai otoko.since you want to watch a jdrama,you may also chack that out ;)