Since you asked about rom-coms, I went through my DL to see what I could find. Sadly, I can't say that I would classify any of the Japanese dramas I've seen as strictly romantic comedies. Plenty of romance dramas, plenty of funny dramas. So what I'm going to do is recommend a few Jdramas that I would classify as romance, even if others might classify them as sports, school, workplace, or family dramas. I don't do tragedies, so none of them are going to pull a 49 Days plot twist at the end :) Take a look at the synopsis for each one and hopefully you'll find one or two that interests you.
Anego
Atashinchi no Danshi
Bokura ga Ita Kouhen/Bokura ga Ita Zenpen (2 part movie - very good!)
Buzzer Beat (loved it!)
Hana Kimi (the original, not the remake! One of my all-time favorites!)
Hana Yori Dango (still my favorite version of Boys Over Flowers)
High School Debut (movie)
Kimi wa Petto (a favorite)
Lovely Complex (movie)
Mei-chan no Shitsuji (LOVE LOVE LOVE)
Natsu no Koi wa Nijiiro ni Kagayaku
Ouran High School Host Club
Paradise Kiss (movie, and a favorite)
Pride (LOVE LOVE LOVE)
Rich Man, Poor Woman (loved it)
I would also recommend Zettai Kareshi, but that may be my Mizushima Hiro crush talking :) Love Shuffle and Nodame Cantible were okay for me, but I don't seem to find NC as awesome as everyone else does. And if you're willing to watch really old dramas, Kimura Takuya's Long Vacation (made in 1995) was a fun watch.
