Mahouka Koukou no Rettousei: Nyuugaku-hen, Shinmai Maou no Testament Recommendations
Both Male protagonists love and want to protect their sisters and will go to any lengths to do so. Both female characters want more than a brother sister relationship with the male protagonist. Both male characters are very strong and intelligent, they work best under pressure from the enemy. Both manga's share Action, magic, Fantasy, Romance, Shounen, and Supernatural genre elements.