Similarities between Bleach and Naruto:
Ishida Uryuu and Uchiha Sasuke in attitude. Uryuu hates shinigami, though not as much as Sasuke hating Itachi. Both have black hair, rival of the main character, and loners.
Kurosaki Ichigo and Uzumaki Naruto in hair color. Orange and yellow are pretty simioar, aren't they? Both of them are t the same age, have their own 'darker half' (Hichigo and Kyuubi ). They belong in a group similar to themselves (shinihami and vizard, to ninja and jinchuuriki). Aside from that, they are the main character, have short spiky hair, at least one girl in love with them (Orihime and Hinata), and have a habit of sacrificing themselves to save people regardless of enemy or not. Annnnnd, they get teased a lot.
Espada and akatsuki. Both sides have a ruler obsessing over world domination. They have 10 members, and work in pairs. They both have a creepy person (Nnoitra and Orochimaru), a violent person (Grimmjow and Hidan), a ruler of a place with a god-complex (Barragan and Pein), a woman that don't speak very much (Neliel and Konan), somebody dark (Ulquiorra and Itachi), a person that looks like a girl (Szayel and Deidara), a very annoying person (Gin and Tobi), and A person that relies on brute strength (Yammy and Kisame).
Rukia and Sakura. Both likes to hit the main character (Ichigo and Naruto), both the first female main character to be introduced in the story. Very knowlegable.