@mike32 I think within manga/anime/light novels the "fevered" school-age character is regularly used as a plot device to reveal suppressed or unconscious desires (and thus propel the plot), much in the same way that alcohol or drugs would for adult characters in fiction. As for Japanese children getting more sick on average than other children in "developed" countries, I doubt it. But if you are a true non-Japanese otaku, sick Japanese bodies are pretty much gospel.
Too... damn... cute... main systems... can't... handle...
executing cuteoverload.exe... AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!!!!!!
Main systems restarting...
Main systems online...
Resuming cuteoverload.exe... AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!!!!!!