I don't know what "Internet stereotype" is supposed to imply, but you won't live in Japan long before some Japanese friend takes you aside and warns you about the phenomenon of tatemae vs. honne, a Japanese person's public expression of feelings vs his true, carefully hidden feelings. If you learn to read Japanese, you'll notice whole shelves in the big Japanese bookstores devoted to the analysis (mostly by Japanese authors) of differences between Japanese culture and others, such as why the tatemae/honne distinction, present in all cultures, is so extreme in Japan.
Decades ago, anthropologist Ruth Benedict discussed this issue (among others) in her book, "The Chrysanthemum and the Sword", which was held in high esteem by the Japanese post-war generation. You might start with that.
I appreciate the readings and will definitely check it out. I've noticed the fetishization of Japanese culture (positive and negative) on the Internet so I'm immediately suspicious of any broad generalizations I see of Japanese people.
I wouldn't just call it an internet stereotype. Have you tried investigating this yourself? It should not be hard to find articles, Youtubers, and bloggers discussing this. Or have you lived in Japan, or have many Japanese friends?
Decades ago, anthropologist Ruth Benedict discussed this issue (among others) in her book, "The Chrysanthemum and the Sword", which was held in high esteem by the Japanese post-war generation. You might start with that.