{
  "spec_version": "3",
  "endpoint": "decisions",
  "stock_code": "5401",
  "company_name": "日本製鉄",
  "content_lang": "ja",
  "meta_lang": "en",
  "canonical_url": "https://the-shashi.com/tse/5401/",
  "api_url": "/api/5401/decisions.json",
  "updated": "2026-08-05",
  "license": "© 2026 Yutaka Sugiura. All rights reserved.",
  "attribution": "The社史 (the-shashi.com) — https://the-shashi.com/tse/5401/",
  "count": 8,
  "description": "Index of this company's management decisions. One decision = one endpoint: follow api_url for the full dossier (background, the decision itself, outcome, quoted primary sources and references).",
  "decisions": [
    {
      "slug": "yawata-fuji-merger-friction-1970",
      "url": "/tse/5401/decisions/yawata-fuji-merger-friction-1970/",
      "api_url": "/api/5401/decisions/yawata-fuji-merger-friction-1970.json",
      "year": 1970,
      "month": 3,
      "type": "reorganization",
      "title": "八幡・富士合併後の内部統合と「双頭の巨人」の摩擦",
      "subtitle": "世界最大の鉄鋼会社は、旧二社の「水と油」の企業文化をどう束ねようとしたか",
      "status": "implemented",
      "status_label": "実施"
    },
    {
      "slug": "yawata-fuji-steel-1970",
      "url": "/tse/5401/decisions/yawata-fuji-steel-1970/",
      "api_url": "/api/5401/decisions/yawata-fuji-steel-1970.json",
      "year": 1970,
      "month": null,
      "type": "merger",
      "tags": [
        "ma-merger"
      ],
      "title": "八幡製鐵と富士製鐵の合併・新日本製鐵の誕生（1970年成立）",
      "subtitle": "なぜ「世紀の合併」は公正取引委員会との2年がかりの攻防を経て成立したのか？",
      "status": "completed",
      "status_label": "成立"
    },
    {
      "slug": "structural-reform-1987",
      "url": "/tse/5401/decisions/structural-reform-1987/",
      "api_url": "/api/5401/decisions/structural-reform-1987.json",
      "year": 1987,
      "month": 2,
      "type": "restructuring",
      "title": "第4次合理化と管理職への「能力賃金」導入",
      "subtitle": "構造不況下の新日鉄は、日本的経営の年功・平等にどこまで手を入れたか",
      "status": "implemented",
      "status_label": "実施"
    },
    {
      "slug": "mittal-alliance-2007",
      "url": "/tse/5401/decisions/mittal-alliance-2007/",
      "api_url": "/api/5401/decisions/mittal-alliance-2007.json",
      "year": 2007,
      "month": 7,
      "type": "alliance",
      "tags": [
        "cp-crossholding"
      ],
      "title": "アルセロール・ミタルへの対抗——ミタルとの提携覚書と3社連合の資本防衛",
      "subtitle": "世界最大の鉄鋼メーカーに、対抗軸で抗うか、実利で歩み寄るか",
      "status": "implemented",
      "status_label": "実施"
    },
    {
      "slug": "nippon-steel-sumitomo-metal-2012",
      "url": "/tse/5401/decisions/nippon-steel-sumitomo-metal-2012/",
      "api_url": "/api/5401/decisions/nippon-steel-sumitomo-metal-2012.json",
      "year": 2012,
      "month": null,
      "type": "merger",
      "tags": [
        "ma-merger"
      ],
      "title": "新日本製鐵と住友金属工業の経営統合（2012年成立・新日鉄住金の誕生）",
      "subtitle": "なぜ国内首位と3位の高炉メーカーは合併し、粗鋼世界2位の鉄鋼会社を生んだのか？",
      "status": "completed",
      "status_label": "成立"
    },
    {
      "slug": "nisshin-steel-acquisition-2016",
      "url": "/tse/5401/decisions/nisshin-steel-acquisition-2016/",
      "api_url": "/api/5401/decisions/nisshin-steel-acquisition-2016.json",
      "year": 2016,
      "month": 2,
      "type": "acquisition",
      "tags": [
        "ma-rollup",
        "ma-rescue"
      ],
      "title": "国内4位・日新製鋼の子会社化——鋼材デフレ下の高炉再編",
      "subtitle": "「なぜ今なのか」——世界的な供給過剰のなかで、進藤孝生社長はなぜ同業の取り込みに動いたか",
      "status": "implemented",
      "status_label": "実施"
    },
    {
      "slug": "3d-nipponsteel-conglomerate-2025",
      "url": "/tse/5401/decisions/3d-nipponsteel-conglomerate-2025/",
      "api_url": "/api/5401/decisions/3d-nipponsteel-conglomerate-2025.json",
      "year": 2025,
      "month": 6,
      "type": "shareholder_proposal",
      "tags": [
        "cp-activist",
        "cp-delisting"
      ],
      "title": "3Dのコングロマリットディスカウント批判と社長再任反対キャンペーンへの対峙",
      "subtitle": "時価総額を超える10兆円の投資と上場子会社の保有は正当化できるか——PBR0.5倍の鉄鋼最大手に向けられた資本規律の問い",
      "status": "proposed",
      "status_label": "進行中"
    },
    {
      "slug": "us-steel-acquisition-2025",
      "url": "/tse/5401/decisions/us-steel-acquisition-2025/",
      "api_url": "/api/5401/decisions/us-steel-acquisition-2025.json",
      "year": 2025,
      "month": null,
      "type": "acquisition",
      "title": "USスチールの完全子会社化——約2兆円のクロスボーダー買収を政治の壁を越えて完遂",
      "subtitle": "縮む国内から離れるために、日本製鉄はなぜ大統領令と訴訟を越えてまで米名門を手にしたか",
      "status": "implemented",
      "status_label": "実施"
    }
  ],
  "by_type": [
    {
      "key": "acquisition",
      "count": 2,
      "url": "/api/5401/decisions/by-type/acquisition.json"
    },
    {
      "key": "alliance",
      "count": 1,
      "url": "/api/5401/decisions/by-type/alliance.json"
    },
    {
      "key": "merger",
      "count": 2,
      "url": "/api/5401/decisions/by-type/merger.json"
    },
    {
      "key": "reorganization",
      "count": 1,
      "url": "/api/5401/decisions/by-type/reorganization.json"
    },
    {
      "key": "restructuring",
      "count": 1,
      "url": "/api/5401/decisions/by-type/restructuring.json"
    },
    {
      "key": "shareholder_proposal",
      "count": 1,
      "url": "/api/5401/decisions/by-type/shareholder_proposal.json"
    }
  ],
  "by_decade": [
    {
      "key": "1970s",
      "count": 2,
      "url": "/api/5401/decisions/by-decade/1970s.json"
    },
    {
      "key": "1980s",
      "count": 1,
      "url": "/api/5401/decisions/by-decade/1980s.json"
    },
    {
      "key": "2000s",
      "count": 1,
      "url": "/api/5401/decisions/by-decade/2000s.json"
    },
    {
      "key": "2010s",
      "count": 2,
      "url": "/api/5401/decisions/by-decade/2010s.json"
    },
    {
      "key": "2020s",
      "count": 2,
      "url": "/api/5401/decisions/by-decade/2020s.json"
    }
  ]
}