The 500 series was the first train in Japan that operate with a speed up 300 km/h. It put into service on 1997 on the Tōkaidō Shinkansen and Sanyō Shinkansen lines. The 500 series has a unique design, which looks like an airplane with a sharp head and round body. In the video below, you can see the high speed and performance of the train. However, it had been replaced by the new N700 series train due to the loud noise it generated and the narrow space inside the car.
Why do you think the engineers designed the train into the round shape instead of the normal rectangular shape?
Jasper's Blog on Trains 