{
  "spec_version": "5",
  "endpoint": "ceo-person",
  "stock_code": "4996",
  "company_name": "クミアイ化学工業",
  "content_lang": "ja",
  "meta_lang": "en",
  "canonical_url": "https://the-shashi.com/tse/4996/executives/ceo/yokoyama-masaru/",
  "api_url": "/api/4996/ceo/yokoyama-masaru.json",
  "updated": "2026-10-26",
  "license": "© 2026 Yutaka Sugiura. All rights reserved.",
  "attribution": "The社史 (the-shashi.com) — https://the-shashi.com/tse/4996/executives/ceo/yokoyama-masaru/",
  "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": "yokoyama-masaru",
    "name": "横山優",
    "kana": "よこやま　まさる",
    "surname": "横山",
    "given_name": "優",
    "hometown": null,
    "education": null,
    "prev_role": null,
    "career": [
      {
        "company": "クミアイ化学工業",
        "from": "1989-04",
        "to": null,
        "roles": [
          {
            "date": "1989-04",
            "role": "入社",
            "event": "入社"
          },
          {
            "date": "2007-08",
            "role": "総務部付K-I CHEMICAL EUROPE SA/NV 出向 取締役社長",
            "dept": "K-I CHEMICAL EUROPE SA/NV 取締役社長"
          },
          {
            "date": "2013-01",
            "role": "国外部長",
            "dept": "国外部長"
          },
          {
            "date": "2013-04",
            "role": "海外営業部長",
            "dept": "海外営業部長"
          },
          {
            "date": "2020-02",
            "role": "執行役員経営管理本部経営企画部長",
            "officer": "執行役員",
            "dept": "経営管理本部経営企画部長"
          },
          {
            "date": "2021-11",
            "role": "常務執行役員経営管理本部副本部長兼経営企画部長",
            "officer": "常務執行役員",
            "dept": "経営管理本部副本部長兼経営企画部長"
          },
          {
            "date": "2023-01",
            "role": "取締役常務執行役員経営管理本部長兼経営企画部長",
            "board": "取締役",
            "officer": "常務執行役員",
            "dept": "経営管理本部長兼経営企画部長"
          },
          {
            "date": "2024-01",
            "role": "取締役常務執行役員経営管理本部長",
            "board": "取締役",
            "officer": "常務執行役員",
            "dept": "経営管理本部長"
          },
          {
            "date": "2024-11",
            "role": "代表取締役社長（現在）",
            "board": "代表取締役",
            "title": "社長",
            "current": true,
            "is_ceo_appointed": true
          }
        ]
      }
    ],
    "references": [
      {
        "source": "クミアイ化学工業 定時株主総会招集通知（2025年1月・取締役候補者のふりがな）",
        "url": null,
        "for": [
          "kana"
        ]
      }
    ],
    "html_url": "https://the-shashi.com/tse/4996/executives/ceo/yokoyama-masaru/",
    "term_start": "2024-11",
    "term_end": null,
    "api_url": "https://the-shashi.com/api/4996/ceo/yokoyama-masaru.json",
    "list_api_url": "https://the-shashi.com/api/4996/ceo.json",
    "predecessor": {
      "slug": "takagi-makoto",
      "name": "高木誠",
      "api_url": "https://the-shashi.com/api/4996/ceo/takagi-makoto.json"
    },
    "successor": null
  }
}