How competitive are masters programs at University of Tokyo and Kyoto University?

I recently finished my 3 year Bachelor's course in NZ (in maths) and looking to do a masters at University of Tokyo or Kyoto University in maths in the near future. Currently, I'm set to do an honours degree (similar to a one year masters course) in NZ in 2025, and hopefully get into Tokyo or Kyoto University in 2026. It seems University of Tokyo has an entrance exam, and some applications where I attach my CV and academic record etc for their math master's program but apparently they only accept about 6 international students each year... I would just like to know if anyone has gotten into a masters program at University of Tokyo or Kyoto University (not necessarily in maths), and how competitive it is to get in. Would I need a perfect GPA or will a decent GPA of around 3.5/4 or above suffice?

Also does anyone know if there are any universities in Japan that will hold online applications for international students? From what I see, only University of Tokyo will hold online exams and applications while most other universities will only hold in-person entrance exams at Japan. I think some private schools will hold online applications but I don't think I have the funds for a private university.

(Just a side note: I am extremely confident with my Japanese skills as I have Japanese parents, attained N1 Japanese, and have also studied Japanese high school level maths in my own time)