I see no reason why they can't discuss it together while figuring out the best way for him to further his education while still being together.
This kinda hits close to home for me in that I have abandonment issues like our sweet little kitty so I understand how much it hurts to have someone you care about so much try to get you to do something away from them. Even IF it's good for him, it can be hard to see beyond the (even erroneous) "I don't want you with me" to recognize it might be a good thing. Considering Ryo has already promised he'd always take Ko with him no matter where he went, I can see Ko taking this *really* hard.
I think, too, it's an adult's bad habit to assume they know what's best, and don't stop to take the younger person's actual wants into consideration. (As a parent, I've certainly been guilty of this myself.) Ko may actually know what he wants to do but it might not be "ambitious" enough in an adult's mind to be "good enough" and Ryo is possibly pushing Ko to do more because he thinks Ko will regret it. But adults often forget that *we* don't want to go and do things by ourselves when we have someone we love and that goes for younger people too. There are a LOT of options out there that could involve Ko working anywhere Ryo goes and I suspect he's actually trying to think of that and Ryo is pushing him to do something else, when Ko may well be perfectly happy with those options.
Sure, Ko could absolutely be behaving stubbornly and refusing (he's certainly shown us he knows how to do that) to pick something or to consider something outside of staying with Ryo.
We just don't know the specifics between the two. I suspect, however, that Ryo (who has shown before he doesn't stop to tell Ko everything) has stuff in mind he hasn't told Ko and so the fault lies in both of them.
I want to see them work it out and happy. I was actually kind of pissed off to see them showing up again. I really wanted to just have them have their HEA and be done with it (especially considering the roller coaster ride Shingo's series has been. >.>)
Not sure if I miss something but they're arguing about, "future plans without him." I can see where its difficult. I'm sure as his lover he wants to stay by Ryouta's side, but as his teacher and an adult and possibly even because he is Ryouta's lover... that he also want Ryouta to grow as a person and see the outside world for himself. After all Ryouta is still considerable young. Maybe it's because he wants Ryouta to be able to try something new like study aboard or go to a faraway college that he say a future without him. For example, if Ryouta wants to be a cook then maybe he could attend a culinary school instead of following the sensei around and now know what he wants to do for the rest of his life.
maybe sensei believes that 3 to 4 years as preparations for Ryota to find/reach his dream to not be too big of a deal for them to be together long term?
Who knows. It could be anything. Guess we just gotta sit and see.
As for Ryota, he just want to be with his lover or a path where he gets to see him more often. If that's the case, neither of them are technically wrong. They just need to fucking sit down and actually communicate.
Love is fucking weird and contradicting because you want to selflessly give everything to the person you love but at the same time you also want them to do the same for you.