So yeah, I'm looking for a romance drama similar to Majo no Jouken. Don't know if many of you have seen it, but it pretty much contained everything that I enjoy watching to: 1) Forbidden love cuz one was teacher, one student (also the student was underage), they tried to keep it in secret at first and so on... 2) They decided to elope/escape (without the intention to marry though, at least not right away), just to be together so they won't get separated, and it was really awesome to see how they tried to cope with living together and how to support themselves 3) The relationship started pretty soon (like in episode 3 already) which I also prefer over the shows where you see that only like in the last or last two episodes 4) Well the age gap was fun as well, especially when the guy was younger than the girl (kinda similar to the first) 5) Both had problems and supported each other (kinda the reason why they got together) and it was also kinda fun that even though an average person would think this is really f*cked up, they still tried to pursue their love So yeah, if you have know any dramas that have similar points to the ones mentioned above, fire them! :)
I think Biscuit Teacher & Star Candy will fit a lot (but not all) of your criteria above.

It stars Gong Yoo and Gong Hyo Jin and it is WONDERFUL.

Biscuit Teacher & Star Candy

And what is so cute is *Tiny Spoiler if you want to read* He is the one that falls for her and pursues her pretty quickly after the first few episodes...he's a gonner after I think maybe ep 3, 4, or 5. It is hilarious and awesome...but with some cool drama in there as well. I highly recommend this. I loved it.
Thanks, I'll check it out! And I probably misinterpret myself a little, the recommended drama doesn't have to include all of the criterias mentioned. :)
Kimi wa petto, Anego (age gap) Coffee Prince (just watch it)
Here are some good dramas for the criterias you mentioned..

Japanese: Forbidden Love, Boku wa Imouto ni Koi wo suru
Taiwanese: Elope\Escape, MARS
Korean: Fast paced romance, Queen In Hyun's Man
Korean: Age Gap, Oh! My Lady
Taiwanese: support through the thoughest issues: Sunshine Angel, MARS

These will most likely suit your tastes judging by the points you offered. :3