Tokyo’s City Hall Eases Dress Code Further

Tokyo Governor Yuriko Koike has quietly expanded the city’s ‘Cool Biz’ energy-saving programme, explicitly allowing male employees to arrive at work in shorts and T-shirts during the hot summer months. The move is the latest iteration of a policy that began 21 years ago when Koike, then environment minister, shocked conservative Japan by scrapping the jacket-and-tie dress code to cut air-conditioning loads.

The original ‘Cool Biz’ concept, which runs from 1 May to 30 September, asks offices to set thermostats at 28°C rather than the usual 26°C or below. The trade-off is that staff shed heavy suits. With the new permission for shorts, the city hall is betting that even more relaxed clothing will make the warmer indoor temperature bearable while trimming electricity demand.

What the Shorts Policy Means for Energy and Workplace Culture

The Energy-Saving Logic Behind ‘Cool Biz’

The policy’s premise is simple: every degree the thermostat is raised cuts cooling energy use by roughly 10 percent in a typical office building. Tokyo summers are notoriously humid, making 28°C a stretch without the lighter clothing. The city hopes that by expanding what counts as acceptable office wear, it can persuade more employees – and potentially private businesses – to adopt the higher set point, reducing the metropolitan area’s peak electricity demand.

How This Changes Workplace Culture in Tokyo

Japan’s business culture is still formal, but the move signals that even government offices are willing to sacrifice a degree of formality for comfort and climate goals. Male employees who previously might have worn short-sleeved shirts and trousers can now officially don shorts. Female staff already had more flexibility with lighter attire. Whether the private sector follows suit will determine if the initiative truly scales, but the city’s stamp of approval removes a psychological barrier for other employers. Driven by climate adaptation as much as cost cutting, the policy reflects a growing acceptance that hotter summers are the new normal.