Takeshi is a senior engineer at the Earthquake and Tsunami Observation Division, Seismology and Volcanology Department, Japan Meteorological Agency (JMA). He is in charge of tsunami information at the JMA headquarters. He holds a Ph.D. degree from Chiba University, Japan. He was also in charge of seismic intensity information operations at the headquarters and Hokkaido volcano monitoring operations at the JMA Sapporo regional headquarters.