Kaken

Kaken (株式会社カケン) is a Japanese construction-services company founded in 1931, originally as a water-supply plumbing business. Based in Nagoya, Aichi Prefecture, the company has built its identity around kankōji — plumbing and mechanical installation work that supplies water and air throughout a building, which it describes as the building's circulatory and respiratory system. Its core contracting services cover air-conditioning, ventilation, sanitary plumbing, and related mechanical equipment for public facilities such as libraries, schools, and government buildings, as well as hotels and commercial facilities. Beyond contracting, Kaken operates the Kita-no-Yu (喜多の湯) chain of super-sento relaxation spas. The company applies its plumbing know-how to self-performed construction and uses a patented bathtub circulation-filtration system that keeps bath water clean while recirculating overflow to reduce water and utility costs. The Yaō branch of Kita-no-Yu has reportedly been ranked first in western Japan for two consecutive years on a major hot-spring website's annual ranking. Kaken markets itself on reliability and continuity, with a stated philosophy of "one person, one role; everyone a lead" (一人一役全員主役) and an emphasis on work-style reform. Its representative director is Nobuo Hasebe. The company is approaching its 100th anniversary and continues to target public and commercial construction projects, primarily in the Tokai region of central Japan.

Kaken was founded in 1931 as a water-supply plumbing company. From its base in Nagoya, it grew into a building-services contractor specializing in kankōji — the installation of piping, air-conditioning, ventilation, and sanitary systems that make buildings habitable. Over nearly a century, the company has worked on a wide range of public and commercial projects, including the Nagoya City Science Museum's science and planetarium building renovation (air-conditioning, joint venture), the Inuyama City Hall sanitary installation, Nagoya University affiliated school building renovation, Nadya Park's youth culture center and international design center (air-conditioning, joint venture), Chikusa Sports Center sanitary installation, the Kasugai Cultural Forum library building (air-conditioning, joint venture), and Osaka Gakuin University's new building (air-conditioning, joint venture, for Kajima Corporation). In addition to contracting, Kaken diversified into spa operations with the Kita-no-Yu super-sento chain, leveraging its plumbing expertise for self-performed construction and deploying a patented bathtub circulation-filtration system. The company states that its Yaō branch achieved first place in western Japan for two consecutive years in a major hot-spring website's annual ranking. As it approaches its 100th anniversary, Kaken continues to emphasize its founding trades while adapting to modern demands for environmental performance and work-style reform.

• 1931

  Founded as a water-supply plumbing company.

• Expanded into general kankōji contracting, including air-conditioning and sanitary installation for public and commercial buildings.

• Launched Kita-no-Yu super-sento spa chain, applying in-house plumbing expertise and a patented bathtub circulation-filtration system.

A long-established, reliability-focused building-services contractor that combines plumbing engineering with spa operations, emphasizing comfort, environmental consideration, and employee autonomy.

• Kankōji contracting

  Plumbing and mechanical installation for air-conditioning, ventilation, and sanitary systems in buildings.

• Kita-no-Yu super-sento

  A chain of relaxation spas operated by Kaken, featuring self-performed construction and patented filtration.

• Bathtub circulation-filtration system

  A patented original product designed and installed by Kaken that circulates and filters bath water to maintain cleanliness and reduce water and utility costs.

1. 1株式会社カケン｜信頼と継続。e-kaken.co.jp
2. 2Kaken - Wikidatawikidata.org