Mrs Suzuishi was the mother of Hiroshi Suzuishi. Little is known about her, except that she clearly loved her son.
At some point in Hiroshi's childhood, Mrs. Suzuishi was fond of giving her son piggyback rides, a memory which he dearly cherished.
The last time Hiroshi saw his mother was when she went to see him off on the space voyage that took him away from Earth. Accompanying her was a man who strongly resembled Hiroshi, who was possibly his father.
It is ultimately unknown what happened to her, though it is likely that she perished either during the initial nuclear bombardment, died in the explosion of Earth or (assuming that the Galra made frequent searches over the planet to find slaves) was either turned into food for the Galran Deathblack Beastmen or turned into a beastman herself.