Mushoku Tensei: Jobless Reincarnation (Manga) Vol. 20

Rudeus was living a happy newlywed life together with his wife Sylphiette, but the sudden arrival of his two younger sisters makes things a lot more complicated. While Aisha is a bona fide child prodigy only too happy to help out around the house, Norn is incredibly average and wants nothing to do with a big brother she loathes. To get away from Rudeus, she's gone off to live alone in the dorms at the University of Magic, but life at school isn't treating her well. Now she's withdrawn into her room, shutting herself off from the world. Is it time for a big brother to intervene?