Yotsuba Koiwai
Age:5
Gender:Female
Height: 107 cmPersonality: She has a carefree and energetic personality, taking delight in simple matters even as she learns about all manner of things in her daily life. In Japanese, Yotsuba's dialogue is written without kanji, making it seem simpler and more child-like, and in a typeface that gives the impression of speaking with high intensity. Her energy is noted by other characters, especially members of the neighboring Ayase family. Her father says of her carefree nature, "She can find happiness in anything. Nothing in this world can get her down." However, when deeply frightened or upset, she does cry, and she has an unexplained fear of anything resembling a bullseye.At the start of the series, Yotsuba is shown as having very little knowledge of the world around her, even for a young child. Things such as swings, doorbells, cicadas, and air conditioners all fascinate and confuse her, although she is not perturbed by her ignorance. She occasionally mispronounces new words and creates neologisms, such as "Yotsubox" as a portmanteau of "Yotsuba's Box", and often repeats, in incongruous ways, phrases spoken by adult characters around her.
Yotsuba is frequently shown drawing, though she is not as good an artist as she thinks she is, and she is an excellent swimmer.