Yotsuya Co-Plus is Japan’s very first privately developed condominium as well as the first of the “Co-Plus” series of apartments.

Although the first condominium was the Miyamasuzaka Apartment built in 1953, this was built by the public housing commission.

Yotsuya Co-Plus was built in 1956 and is now 55 years old. Concrete construction has a useful life of between 60 – 100 years in Japan.

When new, a 3-bedroom apartment was priced at 2,300,000 Yen. At that time, the typical house cost 1 million Yen. In 1956, 1 USD was equal to 360 Yen, so a new apartment in this building would have been 6390 USD, which is about $50,000 in today’s money. However, Japanese salaries in the 1950s were very low, so it would be the equivalent to paying 45 million Yen for an apartment today. During the bubble of the 1980s, apartments in this building were selling for 30 million Yen, but nowadays are selling for 15 ~ 20 million Yen (192 ~ 250,000 USD).

The original residents were wealthy and famous enough to warrant obituaries in the newspaper when they passed away. This building was considered to be very luxurious for its time and unattainable to most Tokyo residents.

Unlike Miyamasuzaka Apartments which had elevators and elevator girls, Yotsuya Co-Plus is a walk-up apartment building.


10 Honshiocho, Shinjuku-ku, Tokyo
Yotsuya Sta. – 5 mins
Ichigaya Sta. – 7 mins


Built: 1956

No. of units: 28
Construction: 5 stories
Construction Company: Sato Kogyo
Developer: Nihon Kaihatsu