University in Japan Without Year 12

Long story short, I would like to study at university in Japan, but don't have a Year 12 certificate. I am 23 (24 in late 2023). I started university late due to personal reasons.

I didn't go to school past finishing year 10 in Australia, but have since completed 2x Certificate III's (roughly equivalent to year 12 - one in Hospitality, and one in IT) and also passed an exam allowing me to study at university. I have currently completed 4x units across 2x semesters (basically 1/2 of the first year) and my GPA is 6.0 on a 7.0 scale (basically a Distinction). I am studying Business, majoring in Economics and a minor in Business Analysis. My university only allows me to spend 1 semester studying abroad, and I would like to do more than that.

My circumstances have recently changed and I'm about to come across approximately $100k AUD (sale of my property), with the ability to sell most of my stuff and travel. I would ideally like to use that to study my degree overseas, and I've decided on Japan for several factors. I have already passed JLPT N5 and am continuing my self-study. I would ideally enter on a working holiday visa to start with, whilst studying at a language school (legal, from what I understand) to bring it up to N2 level. Once done, I would then like to enter Japanese University and I will be 24, almost 25 at that time.

My questions is basically summed up below:

Would I be able to enter a Japanese University (either taught in Japanese or English) like this, or would I have to go back and try and get my Year-12 certificate (will take a year or so). I can't find a lot of info online about this, so figured this as best a place as any.

Thanks for any help you can give me.

The best place to ask is the universities. As your situation is very unique.

I have to agree with the other poster.

Finding an appropriate university in Japan would probably be choice number 1 if I was in your position.

As you might be transferring university, this might be in your advantage specifically if you have already have passed some university classes.

What specifically do you want to study?

Also as a teacher who has taught many students of second languages, there is a huge difference between general and academic language. Also a Japanese degree in Japanese will not mean much in your home country.

In English is another story. If you also have reasonable Japanese, have you thought of finding a forum online for expat students which is in Japanese?

That would give you a much more specific knowledge base compared to a general forum such as us.

might be easier to transfer to an Australian university that has an exchange program with a Japanese university. For example University of New England...

At least you can try out for a 高等学校卒業程度認定試験. The link below is a mere (and quite typical) example of what you need to be qualified to take the entrance exam for University of Tokyo:

https://www.d-pam.com/u-tokyo/2210621/index.html?tm=1#target/page_no=5