Yeah, the first names are good to try to grab at the beginning-its always easy when they use their 'actual' (stage) names, but it isn't always the case.
Yuki Yudzuru (the young looking guy who is in a lot of videos lately) is usually just "Yuki-kun", and a lot of times the actresses use their stage names, but sometimes it takes a while to figure out.
Speaking of names, one thing Japanese is big on is polite titles. So "Oku-san" is used a lot as a polite way to refer to a married woman, and while it does translate to "Wife" (usually someone else's wife, hence the -san) it is weird to translate it as "Wife", since you wouldn't just say "Wife" to someone else's wife (well, you probably wouldn't, lol). Same with calling older women "Oneesan" even if they aren't your big sister-its more like an honorific, but can translate oddly. And one recent video had a sister-in-law that the guy called "Onee-san", and the translation was "Sister-in-Law", which was correct, but it also looks a little odd in English (he used it a lot).
And this went on too long (sorry!) but for some reason different "Boss" titles get translated oddly-one that I see a lot is "Minister" being used for "Bucho", which is a boss type position. But "Minister" in English usually refers to either a government official or a religious figure. I change it to "Manager" or "Boss", because Minister doesn't make much sense (to me).
And don't even get me started on "Senpai" - it just doesn't exist comfortably in English, lol.