Tojo is a lion cub who lived during Mufasa's reign.
Tojo is one of the cubs who listens to Mufasa as he talks about the Great Spirit. Tojo doesn't seem to believe too strongly in the Great Spirit and says that he doesn't watch over him well, since he gets injured quite a bit and has a sprained ankle. Simba suggests that maybe the Great Spirit has a purpose for Tojo's injury.
Later in the story, Simba becomes the "mother" of orphaned blue birds because he takes care of them. Tojo meets up with Simba and begins making wings out of leaves to teach the birds how to fly. Simba leaves Tojo alone with the birds while Tojo is preparing the wings. Upon returning, Simba finds that Tojo has bonded with the birds and has made his own set of false wings, showing that the Great Spirit had a reason for Tojo's injury after all.
Physically, Tojo shares much likeness with Simba. However, there are subtle differences between the two. Tojo's fur is a darker gold, as is his underbelly, which extends to his muzzle instead of stopping at his chest. Tojo has black ear rims, as opposed to Simba's brown, and light eye rims in contrast to Simba's chestnut. Tojo's most noticeable physical difference is the larger, scruffier tuft of fur on his head and his bright blue eyes.
Tojo is a somewhat pessimistic cub, lamenting his tendency to be clumsy and get hurt. When in a good mood, though, he is goofy and willing to help.