It's kind of hard for me to recommend something to you, especially because you've only watched 1 Litre of Tears (I liked it very much btw) and besides that I don't know anything about your likes/dislikes, so I guess I'll just name some dramas that I like very much and that I think you'd like, though I haven't watched that many dramas... Why don't you try Hana Yori Dango? It's a classic here, I guess, and you might enjoy it ^^ Also, Hana Kimi is a nice one, too. And you might like Great Teacher Onizuka (1998) as well. If you also don't mind watching korean dramas, I guess City Hunter is a good one to start.