The offence is said to have been committed on Wednesday at City Park, Nairobi.
Seth Otieno appeared before Kibera principal magistrate Derrick Kuto and denied sodomising the minor.
Otieno faced a second count of unlawfully touching the private parts of the minor without his consent and using his knife to threaten the boy’s life.
He is accused of telling the boy to comply with his demands or face death.
According to the prosecution, the boy was coming from his uncle's house at Pangani's Mlango Kubwa area when he was accosted.
The accused then had a short confrontation with the boy and took him to the park.
He stayed with the boy until he slept then sodomised him.
On realising a strange pain, the boy screamed, attracting passers by who came to his rescue, who held Otieno and took him to Parklands police station where he recorded statements.
He denied the charges and requested the court to release him on reasonable bond terms, saying he has no money.
The boy was taken to MP Shah Hospital where he was treated, a P3 form given and the report handed over to a police doctor.
Kuto ordered Otieno's release upon a deposit of Sh300,000 bond and Sh250,000 bail.
The hearing was set for July 3.