It is revealed in Bleach TYBW that Ukitake had made a deal with Mimihagi when he was a kid— as he was dying from illness— and the entity fused with him, keeping him alive. This explains a lot ...

Kyoraku and Ukitake are the last remnants of Soul Society's older history, known for their close friendship and strength.

This meant that Sosuke Aizen knew all along about Jushiro Ukitake's past and his connection with the Soul King's right hand, Mimihagi. With that, the Bleach manga foreshadowed the existence of ...

Bleach is so long, Ukitake shows up so sparingly, and I haven't watched the original series in so many years, that it's possible that I could be forgetting having previously heard about his ...