Unions in Japan have not been especially strong, at least since McAuthor cracked down on them during the Occupation. They have since often mainly served as a stepping stone to company management for the union leaders. Unions have pretty much been limited to company unions---those directly connected to a company, (e.g. Company A union) as opposed to the broad base unions of the west (UAW etc).

In addition, Japan's labor laws aren't especially well-enforced, unless the wrong person (gov't bureaucrat etc) gets pissed off at the company. A lot of eikaiwa schools and university teachers are in unions and these tend to be more broad based unions open to people of similar employment as opposed to company unions. The problem is, they aren't especially effective either. A strike in Japan is unheard of anymore (JR used to have strikes---and seemingly serious ones before it became a private railroad).

The Asahi Shimbun, pretends to be a liberal newspaper---it is not liberal in the western sense of promoting democracy and individual freedom and rights, but mainly as opposing the LDP (Japan's most obviously nationalist party) and still basically supporting Japan's uniqueness, exceptionalism, and ultimately, purity which must be protected from dirty, dangerous foreign ideas. They won't even negotiate with their own union representing employees---both Japanese and non-Japanese. Liberal? Not at all. Rush Limbaugh is a left-winger compared to them. And if you read here you will see that they are in direct violation of Japan's labor law, but as is usual, the last place one can turn is to the Japanese government for any effective help.