King County Superior Court Judge Bill Bowman handed down the 93-month sentence. The boy, who was charged as an adult, earlier pleaded guilty to first-degree rape in the case.
The boy, who stands 6-feet tall and weighs roughly 230 pounds, assaulted and raped the girl in November 2013. The girl is 4-feet tall and weighs 90 pounds.
The attack came to light after the teary-eyed and soft-spoken girl walked into a Kent Red Lion wearing only a shirt and socks. The girl told hotel employees she had just been raped in the woods behind the hotel, according to charging documents.
Police say the girl's face was swollen and she had scratches and welts on her arms and legs.
The girl told officers a boy that she had seen a couple of times with her older brother came to her house earlier that afternoon and said he had a surprise for her. She didn't know the boy's name, but because she had seen him with her brother she trusted him.
She said she walked with the boy toward a nearby gas station and then into a wooded area behind the Red Lion, where he beat and raped her.
Asked by police where the boy hurt her, the girl pointed to her head and then her groin, according to court documents.
Using the information they'd gleaned from the girl, police were able to track down the suspected rapist within an hour.
The boy originally told police he and the girl went to a grocery story and then returned home. When officers told him they had DNA evidence and surveillance video of the crime, the boy changed his story and said the girl asked him to have sex with her, according to court documents.
Police asked the boy if he thought it was improper to have sex with an 8-year-old, to which he replied, "I thought she was older than that," according to police.
He was booked into juvenile detention for investigation of rape. Then in May, he was transferred to the Regional Justice Center in Kent and held on $250,000 bail after being charged as an adult.