On a recent sunny Sunday morning, Michael M. Honda was kicking back at his 90-year-old mother’s house here, some green tea and rice crackers within arm’s reach. She was off to church, and his younger brother had dropped by to fix the plumbing.

“Oh yeah, I ran across a buddy of yours — he says he golfs with you — a big-set hakujin guy,” Mr. Honda told his brother, using the Japanese word for Caucasian.

Mr. Honda, a Democratic congressman and third-generation Japanese-American, was wrapping up a weekend visit to his district here in Silicon Valley. After attending an event at a local high school, he would fly back to Washington, where his resolution calling on the Japanese government to unequivocally acknowledge its history of wartime sex slavery and apologize for it was steadily gaining co-sponsors.

The resolution was also drawing sometimes surprising reaction in Japan, making Mr. Honda one of the most famous American congressmen in his ancestral land and riling Japan’s conservatives. They have accused a bemused Mr. Honda, 65, of being an agent of a Chinese government bent on humiliating Japan on American soil. During one television interview, an announcer asked Mr. Honda how he could back such a resolution when he has a Japanese face