Yotsuba is a small girl with distinctive green hair styled in four pigtails—the visual reference to her four-leaf clover namesake is pretty obvious. Her personality is what most people lead with when describing her: carefree, energetic, and genuinely delighted by everyday things. Her dad captures it perfectly: "She can find happiness in anything. Nothing in this world can get her down." The Ayase family next door would probably agree, though they're often on the receiving end of her boundless energy. That said, she's not invulnerable—deep fear or sadness does make her cry. She's also got an unexplained, almost phobic reaction to anything that looks like a bullseye.
At the series' start, Yotsuba knows remarkably little about how the world works, even accounting for her age. Swings, doorbells, cicadas, air conditioners—everything fascinates and confuses her in equal measure, but she's genuinely unbothered by what she doesn't know. She has a habit of mispronouncing or misremembering words, inventing things like "Yotsubox" in the process, and she'll repeat phrases she hears adults use in ways that make absolutely no sense. She draws constantly, though fans often note that her artistic skills don't quite match her confidence. As a swimmer, though, she's legitimately excellent.
Her background is deliberately vague. She's adopted, and her origin is a mystery—she claims she's from an island "to the left," which tells you nothing. Koiwai, her adoptive father, picked her up as an orphan in some foreign country and basically ended up raising her before he really thought about it. People sometimes assume she's foreign. She doesn't understand questions about her mother and gets genuinely confused by the idea of having two sets of grandparents. Before moving to their current place, she lived in the countryside with Koiwai and his mother.
She's never been to school. At the start of the series, she doesn't even know what a grade is, and by chapter 35, repeated attempts to explain homework to her have completely failed to land.
Content compiled by AnimeList.moe from publicly available sources.
