Mari Yaguchi and Kenzo Umeda officially got married on March 26.
Yaguchi announced that she had registered the married through her official blog.
"On March 26, 2018, I registered my marriage with an amazing man. I am happy that we get to move forward into the future together after being a relationship for 4 years," she said.
This is the second time Yaguchi has been married. Her first marriage was to actor Masaya Nakamura in May 2011.
In 2013, Nakamura caught Yaguchi cheating on him with Kenzo Umeda. Yuguchi filed for divorce from Nakamura, and continued her relationship with Umeda.
Yaguchi's relationships have been of particular interest since her time with Morning Musume. The idol was caught dating actor Shun Oguri in 2005, causing her to withdraw from the group for betraying her position as an idol.
There are no plans for a wedding scheduled at this time.