I'm so glad I could help! There more that might make for good reading:

"The Stones of Five Colours and the Empress Jokwa" - two rival soldiers work together to protect China. (Source: https://en.wikisource.org/wiki/The_Japanese_Fairy_Book/The_Stones_of_Five_Colours_and_the_Empress_Jokwa)

"The Little Horsemen of Padstow" - a boy follows magical wooden figures as they race around town. (Source: https://mazedtales.org/content/stories/little-horsemen-padstow)

"Shippeitaro" - a samurai liberates a town from a monster cat that's been demanding human sacrifices. (Source: https://www.gutenberg.org/cache/epub/641/pg641-images.html#link2H_4_0005)

I hope you and your son like them!