question about selling online during JET

hi all,

during my college years i had a "business" where i worked as a reseller on mercari/depop. i sold old things i didn't need anymore, and also imported anime merchandise and coach bags from japan and sold them for a larger amount of money. it was a great way to earn some extra cash.

However, JET doesn't allow people to work a second job, and earning a substantial amount of money from reselling apps can technically be considered an income. Does anyone here sell online, even sometimes? Is it safe? Just wanna know so that I avoid issues.

by based_pika