Miruchi

Miruchi and Yuka, during the middle of the series, are grade-school students and good friends of Chiyo-chan, but were separated when Chiyo advanced to high school. Occasionally, though, the three would meet on the way to school and exchange stories about their experiences. Near the end of the series, though, both Miruchi and Yuka had advanced to middle school and proudly showed-off their new uniforms to Chiyo, as well as Sakaki (who was walking with Chiyo at the time). If one were to look closely, Miruchi resembles a younger Minamo Kurosawa (Nyamo), while Yuka is a younger double of Yukari Tanazaki.

(Source: Absolute Anime)