Detective Conan is a great example of the difference between what's considered appropriate for little kids between Asia and North America. https://twitter.com/MinovskyArticle/status/1198487936121094146
Shin Chan is another example of deep differences in cultural values regarding age appropriateness in media. For most of the world it's a silly show for really little kids (that adults like too!). For North America it's for "mature audiences only"! https://twitter.com/Richmond_Lee/status/1002216978730307584?s=19
Terms like "Shonen" "Seinen" "Shoujo" and "Josei" aren't actually very strict. A lot of Seinen comics are actually fairly kid friendly. They just happen to be published in magazines intended for adults overall. Crayon Shin Chan was published in "Weekly Manga Action."