korean drama usually looks more well directed while japanese live action sometime has unnatural scene (like the over-expressive character which makes it annoying and unrealistic), some of japanese live action I watched also looked like a low budget show or made half-heartedly. I could say this because I just watched romance dorama and most of them are shoujo manga adaptation, that's probably why the expressions were a bit weird just like in the manga. But I found some Japanese movie that was great and worth watching, so my opinion doesn't apply to all japanese live action, I suppose.