The epicenter of the tsunami that hit Japan on March 11, 2011 is the epicenter of the magnitude 9.0 earthquake that triggered the tsunami.

The epicenter for the earthquake was reported by U.S. Geological Survey (USGS) and others to be 129 kilometers (80 miles) off the east coast of the Oshika Peninsula, Tōhoku, near Sendai at a depth of 32 kilometers (20 miles).

A global spread of the tsunami can be seen in a related question.

Yes. Sendai was one of the worst hit places by the Tsunami of March 11, 2011.

It is called the Sendai Earthquake of 2011 because the epicenter was nearest the city of Sendai, Japan.

Off the coast of Sendai, a city in North-Eastern Japan.

The epicenter of the earthquake was just off the coast of Sendai, Japan.