The three stars are computer chips 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 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 turned green which represents 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 kindness program that overwrites the competitive instinct and changes Mechatopia of the present.
- Red Star - represents "Love".
- Blue Star - represents "Wish".
- Yellow Star - represents "Competitive Instinct".
- Green Star - represents "Compassion and Kindness".
- The stars and their function are alluded in Amu and Imu's Song.