"He probably got lost and he found these stairs and just started climbing up them," said Kai. "He didn't seem in a big hurry to go. He was just kind of hanging out."
He said the sea lion seemed to be pretty calm until he jumped up onto a cooler and onto a ledge.
"It climbed up on the step and ended up on the side railing of our house. It was just really kind of a scary moment," said Kai.
He then called Animal Control to help get the sea lion down. The pup was taken to the Pacific Marine Mammal Center in Laguna Beach, where volunteers named him Fiddler, after the Broadway musical "Fiddler on the Roof."
Experts said the sea lion was probably just looking for food when he wandered up to the roof.
A marine biologist at the mammal center said "Fiddler" is underweight, probably because he was recently weaned and having trouble finding food on his own. The pup is expected to be fed something akin to a seafood shake, then graduated to herring, before being set free.
Officials say sea lions are mobile and curious and have been found everywhere from a restaurant kitchen to a public restroom.
California sea lions have claw-like toes on their fore-flippers and can rotate their rear flippers underneath them and get around better on land than seals, which use their hind flippers mainly as rudders.
The Associated Press contributed to this report.