Cobalt, Chrom, Kei, and Neon are androids living together in an abandoned house. In order to pay off a huge electrical bill, the four decide to compete for prize money at the Babel entertainment tower. After their first performance, they meet Esora, a boy struggling with the recent loss of his father. The encounter activates a special program within the four androids.
The only thing he left 
behind was this letter.
الشيء الوحيد الذي تركه وراءه
كانت هذه الرسالة
y lo único que me dejó fue esta carta.
y lo único que me dejó fue esta carta.
La seule chose qu’il m’a laissée,
Tutto ciò che mi è rimasto di lui
A única coisa que ele deixou
para trás foi esta carta.
Единственным, что он мне оставил…