1-3 year cultural activities visa to study judo

Hiya folks, as the title suggests I'm interested in going to Japan for a minimum of 12 months to study judo at the Kodokan International Judo Center. I've been training various martial arts since I was 14 (currently 21), and been doing judo for the past 11 months now, coming up on a year. College has been quite a journey for me, and my family was able to save a good amount of money because I work on campus, and am on various scholarships. Therefore, I would like to spend a year after I graduate (May 2027) studying judo, which my parents are happy to fund. The questions I have may be a bit niche but please bear with me!

I have a few questions about the whole process that I'm hoping to get some clarity on:

1) On the visa website for applying for a cultural activities visa, it says to submit "any of the following documents that demonstrate academic or artistic achievements: a letter of recommendation from a related organization, reports on past activities, achievements such as winning prizes and selections, catalog of past papers, works, etc.". I personally don't have any of these because I practice judo for self defence and for the love of the sport/culture. I would still like to study at the Kodokan for their 12 month course, so would a letter from either my previous coach, or someone from the Kodokan itself be sufficient for this kind of application?

2) If they won't accept a letter from a previous coach or sensei from the Kodokan, would I potentially have to go so far as to get a letter from someone in the USA Judo Federation (my current judo governing body, though I am from India) in order to have a relevant recommendation?

3) There is nowhere to register for a membership to the Kodokan online. Will I have to reach out to representatives of the Kodokan specifically to request for a document clarifying the activities and duration of the activities in Japan? Or potentially reach out to them specifically to see if it may be possible to enroll online and I simply missed it on their website?

These are the main questions I have for right now. I will probably edit this if any new ones come to mind! Would appreciate any guidance on this as I'm starting to plan now.

by Twenty_Three_Hundred