Asahi Sunac Main Building (Former Asahi Weapons Manufacturing Head Office Building)

What the Asahi Sunac Main Building is

The Asahi Sunac Main Building (旭サナック本館（旧旭兵器製造本社事務棟）, read Asahi Sunac Honkan) is a two-storey timber office building in Asahimae-cho, Owariasahi, Aichi Prefecture, completed in 1939 and listed as a Registered Tangible Cultural Property on 9 June 2004.

It went up under a different name. According to the city of Owariasahi, it was built as the Asahi branch works of Okuma Iron Works and laid out to naval specifications of the day. The administrative block of that factory later became the head office of Asahi Weapons Manufacturing, and the same building still serves as the head office of the company that grew out of it, Asahi Sunac Corporation. The doubled name on the register records that sequence.

The building covers 338 square metres. Its roof is Yosemune-zukuri, hipped on all four sides and clad in sheet metal. The exterior was originally finished in horizontal weatherboard; sprayed mortar covers it now. The ground floor holds the offices, and reception rooms sit upstairs.

By the time it went up, reinforced concrete had become the ordinary choice for industrial buildings of any ambition, so a timber office block was not a forward-looking decision. What the Asahi Sunac Main Building offers instead is a carefully composed Western-style office in wood. The Agency for Cultural Affairs calls it a good example of the type.

Why it was registered

The Asahi Sunac Main Building was accepted onto the register in 2004 under the criterion for works that serve as a model of design, with registration number 23-0133, in the 42nd round of listings. The Agency for Cultural Affairs files it under second-sector industry, the category for manufacturing.

Two things carried the case. The first is the quality of the interior, built from wood and lime plaster and little else. The second is how much of it survived: the entrance hall and stair, and three rooms along the south side of the upper floor, remain close to their 1939 condition.

Owariasahi's published list of cultural properties, last updated in 2023, makes the point in another way. This is the only nationally registered tangible cultural property in the entire city, sitting alongside prefectural and municipal listings that run to Buddhist sculpture, a burial mound and folk performing arts. A Showa-era industrial building is the outlier in that company.

What to look at

From outside, the reading is straightforward: a broad hipped roof in sheet metal above pale mortar walls. The weatherboard that once covered those walls is gone from view, and photographs from the building's early years show a noticeably different face.

The features the city singles out are inside. Ceilings run high, and the combination of exposed timber and plaster produces rooms that feel composed rather than plain. The sequence from the entrance hall up through the stairwell is the part that has changed least.

The best known detail is a plaster ceiling relief worked with an anchor and a tachibana citrus branch, both emblems of the former Imperial Japanese Navy and a direct echo of the naval specifications behind the design. Owariasahi records that rooms here served as quarters for imperial guests before the war, and that Prince Takamatsu, then a serving naval officer, was received in the building.

All of this comes with a caveat. The interior of the Asahi Sunac Main Building is closed, so the descriptions above rest on the survey records and photographs the city has published, not on anything a visitor can walk in and see.

Visiting the Asahi Sunac Main Building

The Asahi Sunac Main Building is a working head office. There is no public opening, and no notice of one appears in material published by the Agency for Cultural Affairs, the city of Owariasahi or the owner (checked August 2026).

The building stands on company land, and the grounds are private. Do not walk in. If you want to see the exterior, contact Asahi Sunac Corporation in advance and ask. Photography on the site needs the owner's permission, and even from the public road it is worth remembering that this is an active workplace.

Getting there is easy enough. Asahimae Station on the Meitetsu Seto Line is about three minutes on foot. The company's own directions route visitors from Nagoya Station on the Higashiyama subway line to Sakae, then onto the Seto Line at Sakaemachi and out to Asahimae. A taxi from Fujigaoka Station on the Higashiyama line covers roughly five kilometres in about fifteen minutes.

By car, the site is about twenty minutes from the Nagoya interchange on the Tomei Expressway and about ten minutes from the Omori interchange on the Nagoya Daini Kanjo Expressway. Whether visitor parking can be used by anyone who is not there on business is not published, so ask when you call.