Depending on which series or "Cour" you are referring to, covers vastly different parts of the story. Bleach (Original Series) - Episode 4: " Cursed Parakeet "
: Chad, who is normally a pacifist, gets injured trying to protect the bird. It is later revealed that the parakeet contains the soul of a young boy named Yuichi, who is being hunted by a Hollow named Shrieker. Watch Bleach - 004
: This episode is most famous for the scene where several Captains—including Byakuya Kuchiki and Toshiro Hitsugaya—attempt to use their Bankai, only to have them stolen by the Sternritters using "Medallions". Depending on which series or "Cour" you are
: Ichigo’s classmate, Yasutora "Chad" Sado, takes in a talking parakeet that is being pursued by a Hollow. who is normally a pacifist