Because they are not actually black or from black descent but Asians who wear dreadlock. You will be surprised Asians who wear dreadlock have nothing to do with black culture or Africa. Try typing Shiva followers, Saadhu, Tibetian Buddhism, Israeli on google. All of them wear dreadlock. So Africa or blacks don't have monopoly on it.
It is time to accept Asia is whole different continent We have 6000+ years of history and culture of our own.
Or read this. Might help you understand -
https://lionlocs.com/blogs/dreadlocks/history-of-dreadlocks#:~:text=Today%20dreadlocks%20are%20not%20often,in%20different%20parts%20of%20Asia.
I started this without much expectations I just wanted a story with a female protagonist. I've grown so attached to all the characters and I love how age appropriate it is. Can't wait to see what happens next. I'm rooting so hard for Maikeru mainly because he is so fine with his hair up lol
My only complaint really is I wish they we could have had explicitly black characters or characters of African decent instead of putting afros on characters here and there but hey I've given up on representation in Manga a long time ago