22M 21F Do I propose to my girlfriend?

My girlfriend and I have been dating for 6 years and we are moving in together after graduation in May. We pretty much are already living together in my college apartment though, she is with me for 4-5 days a week. I am 22 years old and I'll be 23 in May. My girlfriend is 21. I am taking her on a graduation trip to Japan for 3 weeks in June and I am thinking it may be a good time to propose. I don't think that proposal will mean we will have to get married soon as well, I am fine being engaged for a few years until I have a more stable job to get married and it seems like she has the same mindset. I won a gameshow, so I have the money to get her a nice ring without worrying about it. I also thought it may be a good idea because the Japan trip will be our biggest trip probably for a while, because we have a few months before starting our jobs after college so we were able to take 3 weeks before moving and go. I also know that she is the one I want to marry eventually, so I figure there is no point in waiting. Especially because the Japan trip is so big for us. The only issue is I'm not sure how my parents would react because we are both pretty young. I have pretty controlling parents and I'm worried they would be against it. But also my dad has brought up the idea of proposing in Japan a few times. Please let me know what you guys think. Thank you!