Even just using the pass for a simple Tokyo-Kyoto-Tokyo return is cheaper than walk-up tickets and reserved seats are free.
With the traditional Japan Rail Pass you can plan an itinerary that starts in Tokyo, sets off west and ends in Kyoto before zipping back to Tokyo on the evening of the last day of the pass’ validity meaning you can make a seven-day rail pass last for a full ten days of vacation or more. Even just using the pass for a simple Tokyo-Kyoto-Tokyo return is cheaper than walk-up tickets and reserved seats are free. There is also a 14-day version.