Bio: Yotsuba is one of the twelve sisters of Sister Princess. She loves to play detective and is often saying "checki". She'll investigate almost anything it seems. Yotsuba carries around a magnifier to help with her investigations too.
Opinion: In a show with twelve plus characters, you need a strong personality to stand out. And Yotsuba's obsession with checking things gives her that. Also she looks like a doll when ever she is just sitting there relaxed. As if you see another side of her. Besides she's one of the funner girls in the series. And you can't go wrong with someone who says "checki".