Yuna is Mamoru's childhood friend and neighbor. She is a quite clumsy and often ditzy girl. These qualities cause her to get into many troublesome situations. Since she has known Mamoru since kindergarten, Mamoru knows everything about her, except the thing that Yuna looks at every night before bed. The thing Yuna looks at before she goes to sleep is a photo of her and Mamoru which she cherishes. It is hinted that she is in love with Mamoru, but is afraid to admit her love to him.

*Wikipedia