Raku

is the spirit of a cat that Yuzu Kurosaki once fed.

Character Outline
Raku, in its attempt to follow Yuzu home, was killed by a passing car. It returns sometime later as a spirit of itself with unusually high Reiatsu, attracting Hollows. When the Hollows endanger Yuzu, it transforms into a lion to protect her. Don Kanonji, who organized the Karakura Superheroes in response to the Hollows it was attracting, dubs it the upon first seeing it. He also claims it as the team's "hero mecha" (a common staple in Super Sentai-styled anime), despite it not being mechanical. Transformed, Raku exhibits impressive speed and can surround itself in flame. After the Hollow is defeated, Raku, having fulfilled its purpose, passes on. Nobody other than Yuzu knows that Raku is actually the "lion jet". Yuzu and Karin Kurosaki compare Raku to their brother, Ichigo Kurosaki.

Trivia

 * No reason was ever given as to how Raku was able to transform in to his Lion mode, but it can be assumed that they were awoken in the same manner as those of Orihime Inoue and Yasutora Sado.