Samurai 8: Hachimaruden

He can't run! He can't eat hard food. You can't get any weaker than the boy named Hachimaru. But his dream is to become a samurai. For a boy who can't even survive without the help of his father, that dream seemed impossible. But when a samurai cat appears before him, his whole life will change! A legendary manga creator and a rising star come together to bring you this science fiction samurai epic!

(Source: Manga Plus)