A tsunami is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explosions above or below water all have the potential to generate a tsunami. Unlike normal ocean waves, which are generated by wind, or tides, which are in turn generated by the gravitational pull of the Moon and the Sun, a tsunami is generated by the displacement of water from a large event.

Japanese is the principal language of the Japonic language family spoken by the Japanese people. It has around 120 million speakers, primarily in Japan, the only country where it is the national language, and within the Japanese diaspora worldwide.