Asking for marriage permission in Japanese

I am going to Japan in May for a holiday with my partner of four years and see this as the perfect opportunity to ask for her father's permission to marry his daughter.

Although currently learning Japanese, my skills in the language are not yet up to the standard I feel is currently needed to do this properly, it's very important to me to get this right.

With that said, I was wondering if anybody could help me out with a relatively simple but acceptable way to ask the question? I'm so nervous but really want to impress! I should add I have met her parents on numerous occasions and we get on very well.

Thank you so much in advance for any help with this!

Simon.

Why not ask your girlfriend? She's in a much better position than any of here to advise on how to broach the subject. That was what I did and luckily her father agreed in spite of being rather patriarchal and conservative. In your case there may be a kind of understanding that the two of you will get hiched, and if so there's not much reason to get stressed out over it.