Her name's Hoshie.When her husband shows Astro to her, she at first feels lost in front of Bill Tenma's request to love him as if was the real Tobio.But she is not sure to succeed.
It's a matter of days,though.Then,the two begin to establish a deep and unexpected mother-son relationship. Hoshie tells Astro about his passed away-brother and teaches him something of Tobio's way of being.Hoshie discovers with surprise that she loves him like he was another son. Diametrically opposite is Tenma's attitude, who passed the first moment of affection,starts to reject the little robot.
So much that he sells him to the circus of the cruel Hamegg. Hoshie, desperate and furious, divorced him and often goes to the circus, to see the little robot she learned to love her so much.After a while,she dies,perhaps of heartbreak, considering Astro's conditions in the circus and Tenma's refusal against him. Seized by remorse,Tenma,along with Elefun,builds Astro a mother,based on Hoshie's appearence and temperament.