Press Information

Tamachi Building Co. Invites Local Nursery School Children
to Potato Dig At Company's Rooftop Garden
-- Providing a Fun Opportunity to Learn about the Environment
as a CSR Activity –


On November 6 Tamachi Building Co., Ltd., a Group company of Mitsubishi Heavy Industries, Ltd. (MHI), invited children attending a nearby nursery school to a potato digging event on the rooftop garden of a company-owned building in Minato-ku, in central Tokyo. The event had two aims: to provide the youngsters an opportunity to learn about the environment outside the classroom, and to promote exchanges between employees and people from the local community. Tamachi Building has been holding events of this kind regularly since November 2009 as one way of making social contributions in line with its CSR (corporate social responsibility) commitments. Until now, strawberry picking events have been held each summer and a sweet potato dig, every autumn. In preparation for this latest event, the eleventh to date, the company had planted both sweet and regular potatoes.

Digging potatoes

The potato dig took place on the roof of the Dai Ichi Tamachi Building, which is situated directly across from East Japan Railway’s Tamachi Station in Minato-ku. The rooftop of the main building is home to a garden 219 square meters in area, of which 21.5 square meters is used as a vegetable garden. Cultivated here are 30 sweet potato plants and 24 potato plants in three varieties. Sweet potato was selected for planting because during the summer season it offers a high green coverage ratio, thereby providing excellent heat insulation, while in autumn, harvesting of sweet potatoes, and potatoes as well, makes for a very enjoyable activity. This year’s harvest was again an abundant one.

This year 30 young children, 3 years of age, attending the Minato Municipal Shiba Nursery School participated in the potato dig. Together with municipal staff in charge of promoting community development and local guests, the children first received easy-to-understand explanations, using display panels, about rooftop greening, how it works and what benefits it brings, and were shown photos of the garden’s growth in its various stages. Next came the potato dig itself, with assistance provided by Tamachi Building employees and the nursery school staff. The harvested sweet potatoes were then steamed and tasted, and at the end the children were given sweet potatoes and potatoes to take home.

Each year, children who have participated in the potato dig have later drawn pictures capturing the enjoyment they experienced at this event. This year’s young participants too clearly spent an enjoyable and rewarding autumn day at one of the office buildings within a stone’s throw from their school.

Tamachi Building is an active participant in Minato-ku’s current greening campaign, which targets a 25% cover ratio by 2026. Since May 2009, for six years the company has conducted experiments toward achieving full greening of its rooftops, with subsidy assistance being provided by the local government.

Tamachi Building is a wholly owned MHI Group company established in 1964 to manage the Group’s office building assets. The company’s business scope includes ownership and operation of rental office properties, operation and management of MHI buildings, and related businesses. In line with its business philosophy pledging the provision of safe and comfortable office spaces and high-quality services, Tamachi Building conducts its business reflecting MHI’s CSR Action Guidelines and environment policies while also undertaking initiatives to protect nature and support education during the performance of its own core business operations. Since April 2012 the dining facilities in the Dai Ichi Tamachi Building offer a menu of dishes making use of fresh organic vegetables grown in small plant factories, apparatuses for growing vegetables, that operate on solar power. In this and other ways, the company is undertaking pioneering activities in "in-store production and consumption."

Going forward, Tamachi Building will continue its activities making environmental and local contributions as a way of promoting enhanced employee awareness toward CSR.

 Group photo of the participating nursery school students

 Group photo of the participating nursery school students

About MHI Group

Mitsubishi Heavy Industries (MHI) Group is one of the world’s leading industrial groups, spanning energy, smart infrastructure, industrial machinery, aerospace and defense. MHI Group combines cutting-edge technology with deep experience to deliver innovative, integrated solutions that help to realize a carbon neutral world, improve the quality of life and ensure a safer world. For more information, please visit or follow our insights and stories on