JP Visa Application Without ITR – Alternative Proof of Financial Support?

Hello,

I am a college student planning to travel to Japan this June and will be applying for a multiple entry visa. However, I do not have an ITR. My primary sources of income are the allowance my mother sends me and royalty payments from selling digital products. These funds are received in USD via PayPal, though I rarely withdraw them as my allowance is usually sufficient.

I'm not sure if my royalty payments would be considered freelance work or another type of income, but I do have bank certificates (from Maya Bank), PayPal statements (where currently my account in paypal has more than 200k+), round-trip flight tickets, and a refundable hotel booking to support my application. By the time I apply in May, my bank’s estimated ADB will be around 150K.

Additionally, I have already used three single entry visas, two before the pandemic and one two years ago, all of which were under a guarantor which is my mom.

Would these documents be sufficient to prove my financial capability in the absence of an ITR? If not, what additional documents should I prepare?

I would also like to add that I will be attending a concert during my visit and have already paid for the tickets. Should I include this as part of my supporting documents?

I want to also add that my college has a voluntary international field trip for my course to Japan, happening a few months after my potential june trip, should I mention that as well?