If you want something realistic, then watch dramas that based on a true story like 1 Litre of tears, but i see you've already watched it, Taiyo no uta is also a good one. It is a Jdrama, a good one.
You may want to try Koizora, it is Japanese story phenomenon that started in a cellphone chain messages until it become famous. I highly recommend it.
In kDrama, its very rare to find a drama like that. i think ordinary story is the one i consider realistic like Love story in harvard, Scent of a woman & Two wives.
