Isekai One Turn Kill Nee-san: Ane Douhan
Asahi, a boy who loves video games is killed in a traffic accident and ends up in another world. He tries to enjoy the otherworldly adventuring life he's always dreamed of, but his stats are on the level of an NPC's. He is in big trouble and is being chased by a monster when he hears, "Fear not, little brother!" and the monster is killed in one hit by Asahi's older sister, Maya, who followed Asahi