Can I get a source on that Japanese art?
It's Mae from Fire Emblem Heroes (the art is a perfect example of what Jumpin said).
Is it that Japanese are bad at sex? Maybe, but no, apparently Germans are considered the worst lovers on planet earth :/, so that is NOT it either!
Japanese people are pretty terrible at sex from what I've been told though, and they don't really care about it. They don't have any sexual education except stuff like "how to deal with periods" for girls. I had to explain to my 20 years old Japanese girlfriend what are STDs, and that condoms were not only to protect from pregnancy. They also don't know a lot about oral sex or the opposite sex in general apparently ("what is the clitoris" for example...), I saw several other foreigner guys who said like me that the Japanese girls were surprised and troubled when the guy performed oral sex, because most Japanese guys don't do it (which could explain why Japanese girls are famous for not shaving). Not sure if it's because of the sexism here, but it seems like it's more the guy entering as fast as possible, doing his thing, and finishing without even caring about the pleasure of the girl while she lies on the bed without moving too much.
Maybe the girls I talked to about it only were unlucky to have only bad experiences before, but it seems pretty usual here. I also met several girls who said stuff like "I only want to date foreigners", that could explain it...
EDIT: Sorry about the double post, messed up with the multi-quote!