Hi, I need a ELI5 explanation regarding the nuances of freelancing and being on a student visa. I am so sorry if this is repetitive, there are so many subreddits, and so many different answers that I feel more comfortable asking on my own.

I am coming to Japan in October for 1 year, on a student visa for a language school. Coming from the US. I freelance, every now and then.

Here is what I have gathered:

1. I need the "permission to engage in activities…….." on my visa allowing me to work up to a maximum of 28 hours per week on a Student Visa. I have this filled out already and plan to have this form with me when I land at the airport, or do it online before if I can, but will probably wait.
2. Something about a sole proprietorship? Will I need this as a student? I feel like doing this screams I am more concerned with work than school, which isn't the case. I just need spending money for being a girl and wanting my nails done, and maybe like going out and getting drinks.
3. Time tracking is essential, which I like to do anyway, so I have no problem with this.
4. Taxes?? I have read I might need some help for this, but basically paying twice (US and Japan)? Maybe? Or just filing in the US that I am in Japan and reporting what I made and paying taxes in Japan? help.

Situation: I freelance through Upwork, never more than 28 hours a week (I never even apply to full-time roles)and it varies when I will have a contract or not. I am active sometimes, then inactive others. Right now, I have a client who advised they may need me for some one off projects, that will take about 20 hrs per month, sometime within the next 3 months. For this same client, I usually do about 8ish hours of work and am compensated about 29,000 yen ($200 usd) to do it on an as needed basis monthly. These projects would be separate from that, and the time with the client will be up in 6 months.

Questions:

1. If I do not currently have a contract at the time I land, and I get my permission, how do I notify them I got a contract for a remote company? I read they would want this when it's not in the general permission, but if I don't have this how do I go about that post permission and notifying them?
2. This will at max generate $700 USD a month, on good months, if not, $200 is standard. Is there a max or something I can make while there?

I would like to keep it legal, obvs, and of course I want to try to find work IN Japan, because this isn't long term or consistent so the permission is valid, just concerned about freelancing. Any advice is helpful 🙂

EDIT FOR WHOEVER NEEDS IT:

https://www.moj.go.jp/isa/applications/procedures/nyuukokukanri07_00003.html?hl=en

Per the website:

When operating under a service contract or contracting agreement, etc.
If the standard working hours are not clearly defined due to a service contract or contract, individual permission to engage in activities outside the scope of your status of residence will be required.

(Note) If the standard working hours for the contract are clear, you will be able to work with only the general permission for activities outside the scope of your status of residence as specified in 1 above.

Also, It is possible to obtain BOTH a blanket license and an individual license.
If you already have one of these permits, you can apply for the other permit in addition.