A Buddhist monk, who conducted services in his Diamond Head home, and his wife admitted Friday in U.S. District Court that they had been underreporting their income by hundreds of thousands of dollars.

Bishop Jiitsu Yamauchi, 62, and Lorraine Yamauchi, 69, each pleaded guilty to filing a false joint federal tax return for 2010 by failing to list $938,952 in income.

“We received donations for our nonprofit and used it for personal use (but) did not declare it on our tax return,” Lorraine Yamauchi said.

Jiitsu Yamauchi said through a Japanese interpreter that the donations came from members.

In exchange for the guilty pleas, the federal prosecutor has agreed to drop false tax return charges against the Yamauchis for the tax years 2011-2014. According to an indictment against them, the Yamauchis reported that their income in 2010 was $22,482, was negative for 2011 and 2012 and was $63,664 and $88,943 for 2013 and 2014, respectively. They each face up to three years in prison and a maximum $250,000 fine at sentencing in October.

Also, as part of their plea deal, the Yamauchis agreed that they owe the Internal Revenue Service $621,986 in back taxes for 2008-2014. They handed the court a cashier’s check for that amount Friday.

The Yamauchis registered their domestic nonprofit corporation Sun Mission with the state in 2000. The registration says the purpose of Sun Mission is to provide opportunities for the study of Buddhism and the universal truths.

Jiitsu Yamauchi told The Honolulu Advertiser in 2003 that Sun Mission had about 50 members at the time, though only about 10 people attended services weekly.

The couple registered JYLY LLC in 2012 as a limited liability company that manages the rental properties of Sun Mission.