Japanese National TV program sue consumers

In the article “NHK takes legal action against non-payers”, NHK, a national television company, decided to sue 33 households in Tokyo for unpaid subscription fees. NHK is one of the many TV stations and programs which contributes to the media in Japan. NHK broadcasts daily news, weather, and at times educational programs for both adults and children. NHK used to control the media industry in Japan but today they face competition with other media programs due to the improvement in technology. In the past few years the demand for NHK has decreased because of scandals the workers caused by using the fees collected by consumers for his personal use. Also, the way NHK operates is unfair to the consumers. For when connecting media line into a household, consumers have no choice but to sign a viewership contract with NHK. There is no way out of this contract. When the viewer contract is signed there is no specific law which states the viewers are obligated to pay the fee. NHK makes an assumption that it is an “mutual understanding” the viewers will and should pay. Most of the time, many of the Japanese families do not even watch the NHK, yet are still demanded to pay the fee. These people who come to collect bills continuously come to the house until the bill is paid.
Is NHK allowed to sue the viewers who have refused to pay for the “subscription” even if there is no official contract but just a “mutual agreement”? It just seems unfair to me. What do you think? Do you think the 33 households being sued should be guilty? If you were a consumer, would you pay the fee?