Osamu Kajisa (加治佐 修, Kajisa Osamu) born December 30, 1973, is a Japanese mangaka and former assistant to Masashi Kishimoto. Following his work on Naruto, he went on to moderate success and is best known for the manga series Tattoo Hearts, which was serialised in Weekly Shonen Jump in 2003.
- Happening Go Go!! (1999, Akamaru Jump Summer)
- Nagumo (2000, Akamaru Jump Winter)
- Tattoo Hearts pilot (2000, Weekly Shonen Jump)
- Tattoo Hearts (2003, Weekly Shonen Jump)
- Now and Zen! (2003, Weekly Shonen Jump)
- Nora, Sora (2005, Akamaru Jump Spring)