However, no Japanese team drafted him due to a gay porn video scandal; he ultimately left Japan.

In January 2004, it was widely reported in America that Tadano was featured in a gay porn video A Midsummer Night's Lewd Dream (真夏の夜の淫夢 [jp], Manatsu No Yo No Inmu), three years previously, with Tadano appearing at a press conference organized by the team.

"[3][4] He was sidelined due to an injury early in the 2005 season, but recovered and was shuttled between Cleveland and the Buffalo Bisons for the rest of the year.

On April 4, 2006, Tadano was traded to the Oakland Athletics for outfielder Ramon Alvarado.

He was moved to the bullpen in July after Oakland demoted Colby Lewis and Shane Komine.