Self Disciplined Ninja: A Children's Book About Improving Willpower. Are you constantly trying to help your child break a bad habit? In this Ninja Life Hacks story, Self Disciplined Ninja discovers an underused superpower called WILLPOWER. Whether it's battling procrastination, tardiness, or finger nail biting, Self Disciplined Ninja learns that we all hold the power to overcome challenges. Find out what happens in this comedic book about discovering your willpower.