Interior Design And
Renovation In Tokyo

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Our Works

Based in Tokyo, we offer a wide range of services from interior design & construction to the complete renovation of an entire building.
We can also provide assistance for rental properties.
Our English speaking agent can assist you with your inquiry so please feel free to contact us.
You can check some photos of our past renovation works here.


  • Renovation
  • Roppongi Mansion 01
  • Roppongi Mansion 02
  • Roppongi Mansion 03
  • Roppongi Mansion 04
  • Roppongi Mansion 05
  • The construction of the residential space started by building from a skeleton along with our partner / designer. We have also proposed joinery, home furnishing, curtains and rugs. The design was completed in order to create a relaxing atmosphere that suited the lifestyle of our customer.


  • Renovation
  • Shibuya-ku Residence 01
  • Shibuya-ku Residence 02
  • Shibuya-ku Residence 03
  • Shibuya-ku Residence 04
  • Shibuya-ku Residence 05
  • This residence meets the request for a high-quality design of the children’s room and the entire residential space, allowing the residents to have a comfortable living space. Home furnishing, joinery, curtains, wall painting …etc were carefully planned/chosen through discussions between the interior designer and customer in order to complete a living space that perfectly matched what they had in mind.

What We Do

Service Overview

In recent years, the Japanese residential properties are increasingly popular among foreigners.
These people are not only those who have been posted in Japan, but they also include many who have been attracted to the values of Japanese real estate properties.
However, communication proves to be a difficulty in search of a property in Japan. We have received consultations from developers as well as real estate agencies regarding the difficulty to find the right design company capable of understanding and meeting requests for specific layouts of rooms and special interior design due to the language barrier.
ONE DESIGNS offers services to our customers with our expert knowledge in English.
Although Japanese apartment have many building restrictions with renovations, with ONE DESIGNS experience and expertise , we can meet your requests involving the reconstruction of the building from skeleton.
ONE DESIGNS provides the highest quality workmanship and service to our clients.

Our Service

  • Architectural /Interior design and construction of buildings
  • Our English speaking agent can help you with our experienced and talented team with knowledge in buildings and interior design
  • Proposal and arrangement of furnitures /curtains/ lighting/electronic appliances
  • Assistance for searching properties
  • We can help both rental and purchased properties
  • Apart from residential, we can also help with renovations of properties purchased for investment purposes
  • We also offer services for office design and hotel renovation.

About Us

Company Name



Tokyo Office
Ryoshin Onarimon Bldg.7F,
6-17-15 Shinbashi,Minato-ku,Tokyo
105-0004 Japan

Kansai Office
Umeda pacific building 3F,
2-5-10 Sonezaki, Kita-ku, Osaka,
530-0057 Japan
Tel: +81(0)6-6314-1152
Fax: +81(0)6-6314-1153

Chubu Office
4-14-24 Chiyoda, Naka-ku, Nagoya, Aichi
460-0012 Japan

Interior Depot (Warehouse)
Kiba 2-13-20, Koutou-ku, Tokyo
135-0042 Japan
Milano Office(Representative Office)
Corso Indipendenza, 14 20129 Milano Italia

Managing Director

Koji Umeki




1st class registered architect
Special construction license
Registered real estate agent
Registered temporary staff agency
Registered medical equipment distributor

Group companies

Total 601 employees, 57 bases across the country
Koyou Rentia Co.,Ltd.
Koyou Logix Co.,Ltd.
Koyou Innotex Co.,Ltd.
Koyou Bussan Co.,Ltd.
Koyou Service Co., Ltd.


Nobuhiko Shimada-Shimada Lab Milano

Akinori Inuzuka – Akinori Inuzuka design office

Kazuya Katagiri – kad/katagiri architecture+ design

Contact Us

Our English-speaking agent can help you.
Using our knowledge and expertise we have developed over the years,
we wish to provide the best services to our customers.

Contact by e-mail

Tel: +81-(0)3-6758-3535
Hours: 9:00~17:00
Except Weekends & Holidays

The provided personal information will be used for the following purposes.
(1) Sales/ rental/ delivery of products and relating aftercare services
(2) Notification of information regarding new products/ services
(3) Confirmation of details and responding to inquiries
Information provided by customers will be appropriately handled by KOYOU Holdings Co., Ltd.
based on the personal information protection policy of the KOYOU Group.
*ONE DESIGNS is one of the group companies of KOYOU Group.