Yasuo Hirose, a 70-year-old honorary professor with Yokohama National University, was taken to hospital but later confirmed dead.
"He had an affair with a woman I hate," Emiko Hirose told police, according to the reports.
"I went mad and hit him more than 10 times with a cup."
The wife has been arrested on suspicion of attempted murder, reports said. Immediate confirmation was not available.