Usually Jdrama is always faster pace than any Korean drama. That's because of the duration and episode length. Jdrama also very seldom include fillers and unnecessary side-plots so it could be a downside to certain people who might want that.
So to answer your question, just watch any Jdrama if fast pace (than Kdrama) is what you're looking for. Otherwise here are those I watched this year that I think quite fast pace, but not necessarily good drama:
- Kyouso no Musume
- Akai nurse Call
- Invisible
- Mirai e no 10 Count
- My Family
- Nanba MG5
- Ishiko to Haneo
- Touboui F
These are considered slower pace in my definition but it definitely fast pace than Kdrama:
- Mystery to Iunakare
- Pandora no Kajitsu
- Me no Kabe
- Tokyo Vice
- Shoutai
- Shoujiki Fudousan
- Jashin no Tenbin
