Drama about a shut in or someone who is antisocial.

If it doesn't have to be romance, I can recommand Remote. That's about a shut in inspector getting help from a police woman who goes outside instead of him. There is a tiny bit of romantic feeling between them but that's all.

Taiwanese dramas ToGetHer and Mars are both romantic dramas where the female leads are very shy and introverted.

Then there's Yamato Nadeshiko Shichi Henge and Nobuta wo Produce, both j-dramas, as well as japanese movies Sukitte il nayo, Kimi ni Todoke and Koizora (actually there's a drama of that movie too, I haven't watched it yet though).

For korean dramas there's Fated To Love You (I've only watched the korean version, there's alos a taiwanese version), and I also second Heart to Heart.

Here's a link to a question I had posted a couple months ago that may interest you: http://mydramalist.com/discussions/recommendation-...

You can try Welcome to the NHK!, which can be found on youtube (https://www.youtube.com/watch?v=TLjhuSoTS9w). It's not a drama though, but an anime series. It deals with shut-ins, who are also known as hikikomori/NEETs in Japan. Its a wonderful anime that teaches society about NEETs, the possibilities of why they became shut-ins and how to help them gradually come out of their room/house. It is a very serious subject that is increasing not only in Japan, but in a lot of other countries as well (I heard that Korea's number is rising). Even though it touches on serious issues, such as psychological disorder and suicide, it also teaches important life lessons through it's wonderful plot and characters, and is also quite humorous too.

Cat Street

freeter ie wo kau... he was a shut in for the beginning, then the drama depicts him coming out of it, etc. not much romance though