Some animes are educating kids but all of these are made by distrorting real human bodies. And anime lovers gets inspired to make animes also known by distroting human bodies. So it has good and bad effect at the same time.
I want to know if watching the animes which are not promoting adult content haram.
Is haram as anime contain music which is forbidden in islam, even lowering the volume will be futile as most animes have loud music at the background, there is also blasphemous themes in anime and a waste of time since animes has many episodes and can get addictive.
Anime falls into the category of entertainment. When wondering whether a movie, tv show, or any piece of entertainment is haram to to view, then simply put, if it contains or promote haram then one should avoid it.
One shouldn't view that piece of entertainment when:
If it contains erotica/nudity of any sort, and especially if it isn't something that is really minor or easily skippable.
If the content contains anything that promotes hatred against Islam/Muslims, and/or misrepresents them.
If it contains music, depending on your Islamic opinion on music, then that piece on entertainment might not be allowable for you.
If it stirs up sinful desires in you: https://seekersguidance.org/answers/halal-and-haram/is-it-permissible-to-watch-a-film-that-has-no-impermissible-content-in-a-movie-theatre/
Conclusion
Use these answers and the best of your rationality to decide if a piece of entertainment is worth viewing. If you're doubtful then it is good to avoid doubt but at the same time, don't overthink it.
Sunan an-Nasa'i 5711 (Sahih)
"I said to Al-Hasan bin 'Ali, may Allah be pleased with him: 'What did you memorize from the Messenger of Allah [SAW]?' He said: I memorized from him: 'Leave that which makes you doubt for that which does not make you doubt.'"
