Guys I think one of the issues is that a lot in Japan and Korea, they often frown at celebrities being in relationships so that the fans can see them as "pure angels" that they can push their fantasies onto. As far as I know it usually applies to idols, but maybe it goes for actresses too. On top of that, the acting industry in Japan is really intense and would definitely prevent them from seeing each other so that she can focus. It sucks, but I can understand why the both of them are worried about how their relationship will go.
Also going into the acting industry is a really big decision that is gonna impact a lot in her life even when disregarding her relationship. There's also no telling that she'll be successful enough to hold a stable income. It's understandable that she would be a little hesitant to jump right into it after highschool when she doesn't even have a proper job.
Regardless, I think they'll work out fine so long as they talk about it together (and they probably will soon).