You are a freaking genius. Golden Fox with System is sooooo good. Ive been reading it nonstop for the last 3 days. Plz plz plz keep publishing. You have a new biggest fan and thank you some much for the good read!
SUP lruska. I recommend you read the article on this link, it helps a lot and will definitely improve and maybe make you notice mistakes you didn't know you have committed or improvement you hadnt thought of, but know that its just a guide, no a rule on how to write.
Give it a read, its not long. Im sure you will be surprised
Did you thought about having Theo filming Yui do something cute and possibly sharing it on isekai website COUGHYOUTUBECOUGH ?
This one i am less sure: just in one sentence saying -> a surge of videos about grand daughters began to appear in order to compare against Yui (done by idiot/pampering parent/grand parent). Or just to also be popular.