Yeah, yeah. A couple go through a lot to finally together then family issue that one of them know all along, and boom "I can't be with you".
Yeah. We've seen a lot of manga like that.
She just give prez reason to stay in Japan.
That way, he can help Kaguya takedown Shinomiya and he can also take both Kaguya and his father family back. It's win-win for both of them.
He want to retake his father company. I think that's the reason why prez should be stay in Japan. That way, he will be able to help Kaguya take down Shinomiya (which also Kaguya intention) and get both his father company and Kaguya back.