Mari Yaguchi
Japanese female singer, talent and television presenter (1983-)
Mari Yaguchi (矢口真里, Yaguchi Mari; born January 20, 1983) is a Japanese singer, actress, and television personality. She joined the girl group Morning Musume in 1998 as a second generation member and was the leader of subgroups within Hello! Project, such as Mini-Moni, Morning Musume Sakuragumi, and ZYX. After leaving Morning Musume in 2005, Yaguchi has continued to appear on television in dramas and variety shows.
Career
1998-2005: Morning Musume
Yaguchi became a member of Japanese idol girl group Morning Musume during the second generation auditions in 1998. In 1998, she also became a member of Tanpopo, one of Morning Musume's sub-groups. During her time with Morning Musume, her solo line "Sexy Beam" from their 2000 single "Koi no Dance Site" became a media phenomenon and became closely associated with her.
In late 2000, Yaguchi founded Mini-Moni, a sub-group of Morning Musume and Coconuts Musume featuring members who are 150 cms. and shorter, as their leader. She left the group in 2002 after the release of Mini-Moni the Movie: Okashi na Daibōken!, which explained a fictional account behind her reasons for leaving. In 2003, she participated in the girl groups ZYX, Romans, and Morning Musume Sakuragumi.
“Mari Yaguchi” enters the record as japanese female singer, talent and television presenter (1983-). Crown Archives preserves that source wording while asking what Mari, Yaguchi and Japanese can confirm, complicate or overturn.
Why this record matters
“Mari Yaguchi” is worth following because a concise public description often conceals a longer documentary argument. Here, Mari, Yaguchi and Japanese provides the most credible route into that argument.
The entry’s evidential value lies in the named roles, institutions and publications that can be tested against primary documentation. The source revision retrieved here is dated Aug 24, 2026. The linked authority identifier is Q1142098. VIAF identifies the subject as 257323500. 3 of 3 selected statements include explicit references; 1 carry qualifiers and 0 use preferred rank. The first chronological checks are 1983, 1998, 2005 and 2000.
Public reputation and documentary evidence do not always develop together; absence from a summary is not evidence of historical absence. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Read biographical claims against dates, named institutions and the cited references. Distinguish a subject’s later reputation from evidence produced during their lifetime.
- Establishing names and roles
- Building a first chronology
- Locating cited institutions
Personal papers, civil or court records, institutional files and the scholarship cited by the source.
Three-step research path
- Establish the record: confirm the title “Mari Yaguchi”, its source revision and the description used here.
- Expand the search: follow Mari Yaguchi primary sources, Mari Yaguchi archive and Mari research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Mari Yaguchi”?
- How has the subject’s reputation changed across later accounts?
- Which claims depend on a single source or contested interpretation?
Search terms from this dossier
This entry incorporates text from “Mari Yaguchi” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.