Prayer in Nichiren Buddhism is fundamentally a vow.

Buddhism Day by Day

Wisdom for Modern Life by Daisaku Ikeda
Tuesday, August 6, 2013:

 

Prayer in Nichiren Buddhism is fundamentally a vow. It is a pledge or commitment to follow a chosen course of action; it is a declaration to challenge a clear objective. As such, how could anything be more wonderful than the vow to realize our personal human revolution and actualize the goal of world peace?