Ruu

Ruu is an alien baby from Planet Otto, who can levitate and perform telekinesis on objects. He develops a deep love for Miyu and Kanata, thinking of them as his parents, and often helping them. He uses his abilities at inappropriate times, causing great trouble for Miyu and Kanata. Although he is a baby, he understands everyone. Ruu does not like when Miyu and Kanata fight, as he demonstrates in the 25th episode "With Ruu-kun at the Department Store". In that, Ruu makes peace between his two "earth" parents. He is also revealed as an ordinary baby, who cries and laughs as "earth" babies do. To keep others from learning the truth about Ruu's identity, he is referred to as Miyu's little brother (although Ruu denies that, and insists on calling Miyu "Mama". Ruu believes Miyu and Kanata are his real parents, and does not learn the truth until the end of the series). In Shin Daa! Daa! Daa!, he finally saw and remembered his two "earth" parents after the accident. Ruu also develops feelings for Miu Saionji (the daughter of his earth parents) and confesses to her throughout the manga.