{
  "spec_version": "6",
  "endpoint": "ceo-person",
  "stock_code": "4307",
  "company_name": "野村総合研究所",
  "content_lang": "ja",
  "meta_lang": "en",
  "canonical_url": "https://the-shashi.com/tse/4307/executives/ceo/minaguchi-koichi/",
  "api_url": "/api/4307/ceo/minaguchi-koichi.json",
  "updated": "2026-10-29",
  "license": "© 2026 Yutaka Sugiura. All rights reserved.",
  "attribution": "The社史 (the-shashi.com) — https://the-shashi.com/tse/4307/executives/ceo/minaguchi-koichi/",
  "source": {
    "person": {
      "primary": [
        "有価証券報告書（役員の状況）"
      ],
      "extraction": "EDINET の XBRL から機械抽出した役員表を土台に、雑誌記事・社史・報道で経歴と出自を補完",
      "caveat": "在任区間は career の is_ceo_appointed が正本。退任年月は次の代の就任年月から決まる"
    }
  },
  "person": {
    "slug": "minaguchi-koichi",
    "name": "水口弘一",
    "kana": "みなぐち　こういち",
    "surname": "水口",
    "given_name": "弘一",
    "origin": "外部出身（親会社の野村證券から転出）。引受畑を歩んで同社取締役副社長を務め、1987年12月に旧・野村総合研究所社長へ転じ、1988年1月の野村コンピュータシステムとの合併後も新会社の社長を務めた",
    "origin_type": "外部出身",
    "hometown": "静岡県",
    "education": "東京大学経済学部経済学科 (1955)",
    "education_source": "https://www.nri.com/data/jp/news/files/900037420.pdf",
    "prev_role": "野村證券取締役副社長",
    "career": [
      {
        "company": "野村證券",
        "from": "1955-04",
        "to": "1987-12",
        "roles": [
          {
            "date": "1955-04",
            "role": "入社",
            "event": "入社"
          },
          {
            "date": "1973-06",
            "role": "秘書室長",
            "dept": "秘書室長"
          },
          {
            "date": "1974-11",
            "role": "引受部長",
            "dept": "引受部長"
          },
          {
            "date": "1976-12",
            "role": "取締役",
            "board": "取締役"
          },
          {
            "date": "1979-12",
            "role": "常務取締役",
            "board": "取締役",
            "title": "常務"
          },
          {
            "date": "1983-12",
            "role": "専務取締役",
            "board": "取締役",
            "title": "専務"
          },
          {
            "date": "1984-12",
            "role": "取締役副社長",
            "board": "取締役",
            "title": "副社長"
          }
        ]
      },
      {
        "company": "野村総合研究所",
        "from": "1987-12",
        "to": null,
        "roles": [
          {
            "date": "1987-12",
            "role": "代表取締役社長",
            "board": "代表取締役",
            "title": "社長",
            "is_ceo_appointed": true
          },
          {
            "date": "1994-06",
            "role": "相談役 理事会議長"
          },
          {
            "date": "1994-06",
            "role": "社長退任（次期社長登用による推定）",
            "title": "社長",
            "event": "退任",
            "estimated": true,
            "is_ceo_retired": true,
            "retirement_basis": "next_ceo"
          },
          {
            "date": "1997-06",
            "role": "顧問",
            "title": "顧問"
          }
        ]
      }
    ],
    "html_url": "https://the-shashi.com/tse/4307/executives/ceo/minaguchi-koichi/",
    "term_start": "1987-12",
    "term_end": "1994-06",
    "api_url": "https://the-shashi.com/api/4307/ceo/minaguchi-koichi.json",
    "list_api_url": "https://the-shashi.com/api/4307/ceo.json",
    "predecessor": null,
    "successor": {
      "slug": "hashimoto-shozo",
      "name": "橋本昌三",
      "api_url": "https://the-shashi.com/api/4307/ceo/hashimoto-shozo.json"
    }
  }
}