In this short scene, we learn that Yuma has made a promise to her sister that they will be together forever. Yuma is sorry that she didn't live up to her promise, but she's also happy that she and her sister are together. She says that she'll do her best to be with her, too, but that she doesn't want her sister to tell her mom about it, because that's her job. She's happy because she feels like she finally heard her sister's wishes, and that she can be with the one person she loves the most.