Taiso Samurai

Joutarou Aragaki, also known as Samurai, had to give up gymnastics for a while after suffering a shoulder injury and dealing with his wife's passing. However, five years later, he's back training with the Japanese team, but his progress is stalled. His coach thinks it's time to retire, but Joutarou's daughter Rei wants him to keep going. They get an unusual visit from a man who calls himself Leonardo, who claims to be a ninja and seems interested in watching Joutarou compete again.