Before joining the Wildcat and the family of thieves, he originally resides by the downtown '4th Street Orphanage'. This Orphanage isn't a full-time one though, rather it is a part-time private property orphanage and a black market, selling body parts of the non-adoptable aged kids. The boy never really know this.
During an excruciatingly boring field-trip, River decided to take a break on a bench by the bay. While taking a nap, the Orphanage's field-trip bus forgot about him and left him behind. He woke up, finding a brunette girl asking him if he was lost. He shook his head before realizing the Orphanage's bus is gone. Knowing that he's lost, the girl urge him to follow her to her family since it is getting dark.
This family consist of an old man and 3 other kids namely; Pat, the brunette girl who brought River to the family and has the habit of bringing home ‘pets’, Olivia, a blonde spunky kid and Felix, the only rabbit in the house. They grew attached to the lost boy within minutes of introducing himself that, instead of sending him to the police, they legally adopt him to the family. The family learned that he didn't have an identity like his name or his birthday. So just like what the old man did to the kids, he decided that the boy's birthday will be on the first day of summer and named him 'River'.
As few years passed by, the family grew close. Their old man taught and trained them how to be a thief, dodging attacks, pick locks and stealing, as they are poor at that time. River didn't mind it though, because this family is something that he unknowingly crave for. It's only until that one day when Felix got caught trying to steal an item from an important person working in a scientific research facility that the family went apart. That person alerted POSRA and they retraced Felix’s path to their apartment, a.k.a their hideout. Luckily, the family knew they were going to raid their place and escaped. Before their old man turned himself in, for the POSRA to no longer track him down with the kids, he lead them to an Orphanage called Wildcats.
The old man pleaded secretly for the oddly colored hair rabbit for him to take care of the three kids. He offered his priced possessions and money for the owner’s Wildcat Orphanage (as well as giving personal money for the kids just in case they want to leave) before leaving them and turning himself in. Since then, the trio stayed in with the Wildcats, waiting for their old man to come back, until realization hit them when they saw his mugshot on a newspaper. It looks they’re going to stay in with the Wildcats for real.