Japan’s best-designed offices — one company, one walkthrough
OFFICES › MARUNOUCHI, TOKYO › MITSUBISHI GAS CHEMICAL

Office · Marunouchi, Tokyo · Manufacturing

Mitsubishi Gas Chemical — Marunouchi: a storeroom in the basement turned into a secret base

Mitsubishi Gas Chemical’s offices fill the 5th to 7th floors of the Mitsubishi Building, and the split floors made it hard for people to meet. There was no room upstairs for anything new. So the company went down — and turned a basement storeroom and server room into a shared space called Multi Base One.

Company MITSUBISHI GAS CHEMICAL COMPANY, INC. (三菱ガス化学株式会社) ↗Offices Floors 5–7 of the Mitsubishi Building, fixed desksNew space Multi Base One, on B1 — formerly a warehouse and server roomUses Free work space, online-meeting booths, internal events, light exercise, touchdown for staff from other sitesConcept “Sparkling Office”Office design Okamura Corporation
Multi Base One
Multi Base One

Concept

A space built around hubs

The main goal was communication. To draw people down from the office floors to the basement, Okamura designed around “hubs” — points where people meet by chance. A café counter with a coffee maker is one; a library built around a structural column is another.

The look is called Sparkling Office: fresh blue with white, pale wood and touches of gold. And because the client is a chemical maker that wanted to raise environmental awareness from within, most of the finishes and furniture were chosen for their environmental credentials.

Multi Base One
Multi Base One
The bring-your-own library
The bring-your-own library

01 · The blue door

From a dim corridor to somewhere else

In the basement, steel doors line the corridor at even intervals. Only one has a bright blue sign. Open it and the dim corridor gives way to a bright white-and-blue room. Half of it is a café area of pale wood and plants.

Multi Base One
Multi Base One
The café area
The café area
The café area
The café area

02 · A secret base

A library everyone fills

At the centre of the café area, a large column has been turned into a bring-your-own library. Staff share any book they want others to read — business books and technical books, but also etiquette guides and novels. Team meetings happen in cave-like booths, dark inside, that feel like somewhere a child would want to crawl into.

The library
The library
The library and booths
The library and booths

03 · Café spot

Recycled from end to end

In front of a large logo is the second hub, a café spot with sofas. Its upholstery is made from a single material so it can be recycled, and the bench sofas along the corridor are covered in 100% recycled polyester.

The café spot
The café spot
The café spot
The café spot
The café spot
The café spot

04 · Free area

Shoes off, and move

Beyond the solo-work seats is a free area. A raised section, where you take your shoes off, is for light exercise; big cushions let people work while lounging. A large whiteboard wall and tables serve both individuals and groups. Chairs are made from felt of 100% recycled PET bottles, and the floor is linoleum.

At the back, behind steel partitions, is a room with four-person and two-person booths for online meetings, in use almost all day. Its carpet is made from recycled fishing nets.

The free area
The free area
The free area
The free area
The online meeting room
The online meeting room
The online meeting room
The online meeting room
CompanyMITSUBISHI GAS CHEMICAL COMPANY, INC. ↗
DesignOkamura Corporation
Photography© Okamura Corporation (from Okamura’s Design Stories)
Sourceオカムラ Design Stories, “三菱ガス化学株式会社様の事例”, re-reported by WALL ↗
PublishedOctober 2026
OFFICEMILL — explore offices across Japan
Planning an office in Japan?The design and build firms behind the offices on WALL are listed on our Partners page.
SEE PARTNERS