Name: 矢口真里 (Yaguchi Mari)
Date of birth: January 20th, 1983
Place of birth: Yokohama, Japan

Date of debut: May 3rd, 1998 (Member #8)
Graduated: March 31st, 2009

Official site | Official fan club | Official blog 1 | Official blog 2

Mari Yaguchi is a Japanese singer, song writer, author, actress, tv host and Tv-personality

Mari Yaguchi signed up for an audition called Morning Musume Addition Audition, held by the TV show ASAYAN. They were helping Tsunku, a manager, to find three new members for his girl group Morning Musume.

Yaguchi was one of the three winners of the audition, the other two being Kei Yasuda and Sayaka Ichii. They became part of the group in early 1998, and was first featured in the group’s second single, «Summer Night Town».

During her time in Hello! Project, Yaguchi was also part of the group Tanpopo, which released singles alongside Morning Musume. She also participated in shuffle groups Aoiro7, 7nin Matsuri, Sexy8, 11WATER, H!P ALl Stars, and PuriPuri Pink from 2000 to 2005. She has also released several photobooks and idol DVDs.

In 2003 she was put in a group called ZYX with Hello! Project Kids to work as a mentor for them. 

A few years later, a gossip magazine posted paparazzi pictures of Yaguchi dating an actor which caused Yaguchi to withdraw from Morning Musume immediatly. She announced it on a tv show, saying she had betrayed her position as an idol. and that she wanted to move on with her career as an adult. 

The next few years, Yaguchi has been very «bishii» holding fan club events, she was a model for a video game, opened her own restaurant, works as an actress, co-hosts various TV shows and is a frequent guest at variety and talk shows.

In 2009 she graduated from Hello! Project during the 2009 mass graduation. The same year, she joined a TV show called «Quiz Hexagon II». The show formed a group called Hexagon All Stars (ヘキサゴンオールスターズ) after the success of the female group Pabo in 2007. Yaguchi was part of the show until it was taken off the air in September of 2011, releasing several singles, compilation albums and concerts.

The same year, she also released a digital single with Kei Yasuda called "Kimi ni Todoke". She also married in 2010, changing her name to Nakamura Mari.They divorced three years later.

In 2011 and 2012, Yaguchi was a part of  Dream Morning Musume. They released an album and a single, and went on two national tours before going on hiatus.

In 2013, Yaguchi was involved in a scandal, where her husband found her in bed with another man. Yaguchi stated a public apology, was divorced, and announced her retirement from show business. After being absent for one year, she made a one-hour long interview (being really nervous) and announced her return to show business.

She is still working as a talento in Japanese show business and is an active blogger.