Hawk One Corp.

Hawk One Corp. (株式会社ホーク・ワン) is a Japanese housing manufacturer headquartered in Miyamae, Suginami, Tokyo. It operates primarily in the detached single-family home business, handling the entire chain from land acquisition and residential planning and proposals through construction and after-sales maintenance. Its flagship in-house brand for built-for-sale detached homes is MIRASUMO (ミラスモ). The company focuses on the bed towns of the semi-central areas of the Greater Tokyo (首都圏) and Chukyo (中京圏) regions. According to its Wikipedia entry, it sold 3,166 for-sale units in fiscal 2025 and has sold more than 20,000 homes since its founding. Its product line is organized around three interior/exterior color lines — 'cool', 'neutral' and 'rustic' — and three specification grades, Series 3, Series 5 and Series 7, allowing buyers to match a home to their lifestyle. Hawk One became part of the Open House Group. In late September 2018 it entered a capital and business alliance with Open House (now Open House Group), which made it a consolidated subsidiary; the two companies' detached-housing operations covered complementary sales areas and price ranges, allowing the group to span markets from central Tokyo to the semi-central suburbs. Open House later made Hawk One a wholly owned subsidiary through a combination of share acquisition and a share exchange, with Hawk One cancelling its own treasury shares. Within Open House Group, Hawk One's business is positioned as one of the sub-segments making up the group's detached-housing operations, and it accounts for more than 10% of the group's consolidated net sales. Open House Group provides debt guarantees for Hawk One's borrowings and shared services, and a royalty agreement covers use of the corporate brand. Hawk One holds a Minister of Land, Infrastructure, Transport and Tourism real estate transaction business licence (国土交通大臣（6）第6014号), a Tokyo Governor construction business permit (東京都知事（特-7）第115282号) and a first-class architect office registration (東京都知事登録 第61801号), and is a member of the All Japan Real Estate Association. It has won regional No. 1 rankings in the low-rise housing category of the 2023 National No.1 Home Builder Compendium in cities across Saitama, Tokyo, Kanagawa and Aichi prefectures. The company has also faced a notable compliance issue: in December 2010 the Kanto Regional Development Bureau of the Ministry of Land, Infrastructure, Transport and Tourism found insufficient seismic wall quantity and wall-balance nonconformity in 270 wooden two-storey homes it had built and sold in four prefectures after building confirmation between March 1999 and December 2008; Hawk One attributed the problem to design calculation errors and repaired all affected homes free of charge.

Hawk One Corp. is a Japanese housing manufacturer headquartered in Miyamae, Suginami, Tokyo. It built its business around detached single-family homes, handling land acquisition, residential planning and proposals, construction and after-sales maintenance in an integrated manner, and it developed its own MIRASUMO (ミラスモ) brand for built-for-sale homes. Its sales footprint centers on the bed towns of the semi-central areas of the Greater Tokyo and Chukyo regions, and its Wikipedia entry states that it sold 3,166 for-sale units in fiscal 2025 and has sold more than 20,000 homes since its founding. A major turning point came in 2018. At the end of September 2018, Hawk One entered a capital and business alliance with Open House (now Open House Group) and became a consolidated subsidiary. The rationale was that although both companies were engaged in detached-housing-related businesses, their sales areas and price ranges did not overlap, so the combination would allow them to complement each other across markets from central Tokyo to the semi-central suburbs and expand the group's overall operating area, while capturing scale merits and building an integrated production-and-sales operating structure. Open House subsequently made Hawk One a wholly owned subsidiary: of Hawk One's 44,000 issued shares, 26,224 were acquired by Open House, 11,411 were exchanged through a share exchange with Open House, and the remaining 6,365 treasury shares were cancelled by Hawk One. Open House used the share-exchange method in part so that Hawk One's existing shareholders would become Open House shareholders and could share in the value created by the integration. Within Open House Group, Hawk One's business is positioned as one of the sub-segments constituting the group's detached-housing operations, and it accounts for more than 10% of the group's consolidated net sales (excluding intra-group sales). Open House Group provides debt guarantees for Hawk One's borrowings and shared services, and a royalty agreement covers use of the corporate brand. Hawk One has also faced a significant compliance episode. On 8 December 2010, the Kanto Regional Development Bureau of the Ministry of Land, Infrastructure, Transport and Tourism announced that it had confirmed insufficient wall quantity (壁量) and nonconforming wall-balance in a total of 270 wooden two-storey homes that Hawk One had built and sold in Tokyo, Saitama, Chiba and Kanagawa prefectures after building confirmation between March 1999 and December 2008. Wall quantity was 50–70% of the building standard in 28 of the homes and below 50% in 7, though the bureau said there was no immediate danger of collapse. The designs had been outsourced to 27 design offices across the four prefectures, and five architects involved ultimately received business suspensions of three to eleven months. Hawk One explained the cause as design calculation errors and repaired all the homes free of charge. In more recent years the company has continued to adjust its branch network, opening an Ichikawa branch and relocating its Shinjuku branch, and it has issued public warnings to customers about fraudulent door-to-door sales posing as construction contractors, such as the 'roof inspection' solicitation scheme.

• Start of the period during which homes later found to have seismic wall-quantity issues were built and sold after building confirmation.

• End of the period during which the affected homes were built and sold.

• MLIT Kanto Regional Development Bureau announced insufficient wall quantity and wall-balance nonconformity in 270 wooden two-storey homes; Hawk One repaired all free of charge.

• Entered a capital and business alliance with Open House and became a consolidated subsidiary.

• Notice of termination of the custom-built housing business.

• Won regional No. 1 rankings in the low-rise housing category of the National No.1 Home Builder Compendium in multiple cities.

• Sold 3,166 for-sale units in fiscal 2025, according to its Wikipedia entry.

• Opened the Ichikawa branch.

• Announced relocation of the Shinjuku branch.

A housing maker delivering homes designed to be lived in for generations, spanning land procurement to after-sales care, positioned within Open House Group's detached-housing segment.

• MIRASUMO (ミラスモ)

  Hawk One's in-house brand for built-for-sale detached homes, developed around the idea of homes that families can live in for the long term and pass on to the next generation.

• Series 3 / Series 5 / Series 7

  Three specification grades: Series 3 covers basic equipment and functions, Series 5 adds materials and convenience features, and Series 7 is a high-grade specification incorporating Hawk One's housing performance.

• cool / neutral / rustic color lines

  Three interior and exterior color lines — white-based monotone 'cool', light wood-grain 'neutral' and dark wood-grain 'rustic' — each with two color-width variations.

• Insufficient seismic performance in wooden homes

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1. 1株式会社ホーク・ワン｜住まいをつくり、未来をつくる。「ミラスモ」の街づくりを提案する会社hawk-one.jp
2. 2会社情報|ホーク・ワンhawk-one.jp
3. 3家づくりのこだわり|戸建分譲事業|ホーク・ワンhawk-one.jp
4. 4本社・支店情報|会社情報|ホーク・ワンhawk-one.jp
5. 5Hawk One - Wikidatawikidata.org
6. 6ホーク・ワン - Wikipediaja.wikipedia.org