Inside Japan's corporations, the culture emphasizes the success of a company as a whole to be more important than any single individual, which might explain why one study found that 63% of Japanese felt guilty for taking paid leave. But perhaps more concerning is this: Long work hours don't necessarily mean high productivity. In fact, Japan has the lowest productivity amongst the G7 nations. Earlier I mentioned the term karoshi: it means death by overwork. It's legally recognized by the government and usually is marked by a heart attack, stroke or suicide due to stress. There's hundreds of cases of karoshi reported annually, although some argue these cases are under-reported and that the real number could exceed that by up to 10 times. An employee of the advertising firm Dentsu jumped to her death in 2015. The cause was said to have been depression caused by overwork. The case generated widespread attention and renewed calls to change the long working hours and illegal unpaid overtime highly common in Japan. The firm was fined for violating labor standards because she was reportedly forced to work more than 100 hours of overtime per month. The company's CEO even resigned over the controversy. After the death, Dentsu made some changes within the company.