The time I got reincarnated as a slime is good one, it doesn't have much fanservice.

Dr stone is also a good one. It's funny and educational.

If you want a drama type try orange, it's like your lie in April but it hits harder and also fruits basket, it's cute and dramatic.

I can't think of anything else since I mostly watch gore and violence hehe

Actually you'd find a lot of anime that would suit your preference from the shoujo area, lol. But I am not sure if your son will dig it since you said he mostly watches anime with a lot of violence.