Omg this is so late im sorry lol. But here is one i really like (its my fav after Dr.Stone and Death Note):
“Seraph Of The End/Owari No Seraph”
It’s about a little boy being sent to an orphanage at the age of 8, because of special reasons. He is yelling and is not interested in being friends with others because of his traumas. A boy at his age named Mikaela (Mika) is trying to be friends with him and says everyone here at the orphanage is family. Yuichiro (the main character) yells that he doesn’t have a family. The other kids at the orphanage say that they also don’t have a family. The exact same day the vampires takes over Tokyo and spreads a virus that does that everyone over 13 dies. So their teacher dies and the vampires takes all the children in Tokyo into their territory and once a day they take blood from them to survive. The kids were stuck in there for years until Mika and Yuu is 12 years old and wants to escape with everyone else…
I really like this series you can watch it on Netflix (if you have it) or on some random website. The anime unfortunately only has 2 seasons but you can still read the manga online. Sorry if this text is too long im a yapper.