MyGO! My Little Sister Has Been a Vegetarian for Ages and Has a Huge Treasure Chest

Nagasaki Soyo, owner of a gigantic treasure chest! And by a twist of fate, she became my stepsister! The problem is, she's very wary of me, a stranger who suddenly appeared in her life. How am I supposed to get along with her...? No matter what I do, she acts like she wants to keep me at arm's length. Maybe I should start by getting on good terms with her friends? ..."Sorry, Soyo, but could they be your sisters-in-law?" ...