Nihon Chinbotsu: Kibo no Hito

In 2023 in Tokyo, Prime Minister Higashiyama Eiichi pushes for COMS at the World Environment Conference. COMS is a method to liquify pollutants and store it in the crack of the sea floor. Prime Minister Higashiyama gathers young and talented bureaucrats and launches Japan Future Promotion Conference, which is to benefit the future of Japan. Amami Keishi of the Ministry of the Environment and Tokiwa
Koichi of the Ministry of Economy, Trade, and Industry are members of that conference.
One day, Tadokoro Yusuke's article is published in a weekly magazine. His articles warns that Kanto region will sink into the sea. Due to his article, groups begin to hold protests. To ease the situation, Amami Keishi meets with Tadokoro Yusuke, but Tadokoro insists that, in the near future, Izu Peninsula will sink and that will portend the Kanto region sinking. Around this time, Shiina Minori, who is a weekly magazine reporter, talks to Amami about possible corruption between a company and the Ministry of Environment. Amami is uncomfortable dealing with everything, but he takes part in his hobby and goes scuba diving with Tokiwa Koichi. There he faces a shocking event.
(Source: AsianWiki)
~~ Adapted from the novel "Japan Sinks" (日本沈没) by Komatsu Sakyo (小松左京).