Isekai One Turn Kill Nee-san: Ane Douhan no Isekai Seikatsu Hajimemashita season 1 episode 5
Episode title: The Ikusaba Brother and Sister's Big Dungeon Exploration Plan
A new dungeon entrance has been discovered! Tanya asks Asahi to explore it to see if it’s safe. If it is, it will be opened up to all adventurers of every rank. Asahi is excited about taking on a quest by himself, but, alas, it is not to be.
