This is 1990, with a populace sensing an inability for a Japanese government to control itself in regards to Prime Ministers going against the "constitutional amendment procedure".
Aka they are afraid, without any sort of actual events threatening Japan in the first place (this is 1990, before 2001), that Japan's executive power will go ahead and further wrongly interpret the Japanese constitution.
Besides, I am sure you pissed off the USA doing this, because they are (practically) the people who put that in your constitution to control any further Japanese imperialism and support Japanese democracy, which, like what I am saying, is being under minded.
Wouldn't be surprised that a citizen of Japan with suddenly an AMAZING set of lawyers sues the Japanese government.
Toyota Japan patents an experimental prototype hydrogen engine
>1990's
>"Hydrogen fuel does not occur naturally on Earth and thus is not an energy source; rather it is an energy carrier. As of 2014, 95% of hydrogen is made from methane."
>Methane still comes from Saudi Arabia.