The three stars were used as a chip that function as a robot's heart. However, the yellow one that represents competitive instinct eventually caused the robots' evolution to become the same as human and they eventually sought out humans to be their slaves. The green star first appeared when Riruru repaired Pippo's system by using her own yellow star, thus it turned green which represent her kindness toward Pippo.
Near the end of the story, Riruru used both her red star, and blue star, along with the pendant that Shizuka gave her as a substitute for green star, to process the program of kindness that would overwrite the competitive instinct and change Mechatopia of the present.
- Red Star - represents "Love".
- Blue Star - represents "Wish".
- Yellow Star - represents "Competitive Instinct".
- Green Star - represents "Compassion and Kindness".