Counsel assisting Aroha Fletcher said some survivors were treated inhumanely instead of being loved and supported.
She said survivors will speak of being chained like a dog to the table and forced to eat like one, not being given the necessities of life most take for granted, and some were sexually and physically abused.
Fletcher said some of them were belittled and made to feel they did not exist and were nothing.
She said it is important survivor stories were heard.
"The purpose of this hearing is to give them a platform so they can teach the commissioners what they went through and we look at what we need to change going forward so that these abuses don't happen in foster-care again.
"Unfortunately, with what they have been through, they will be sharing the abuses that happened while they were in the foster-care environment, so that's where the state intervened and took them away from their families and placed them into alternative arrangements."
She said some of the survivors went through multiple placements.
"As a child, they started off in one foster family home and they ended up being 37 placements later in another one."
She said it was very hard for the children to form relationships with secure connections with people.
"That would have impacted some of them in later life as adults when you go out into the wild world and you expect yourself to be a reasonable adult and try and form relationships."
Fletcher said the evidence from survivors continued to surprise her.
"You can't believe what some people had to go through as a child.
"Some of these people were only 2, 3 years old.
"When you read these stories it is always shocking. It is not something you would ever expect.
"You just hope it would never happen again to anyone."
The royal commission will hear from survivors and some expert witnesses over the five days set aside.