TLDR ; Rukia e Renji quase morrendo durante o ataque de quincy na sociedade da alma, Eles são levados para o palácio dos reis da alma, curados e recebem treinamento avançado.
Later, Senjumaru Shutara brings Rukia, Renji, and Byakuya to the Royal Guard's Tenchūren so they can be taken to the Royal Palace. Unohana states their condition is too critical for them to leave Seireitei, but the Royal Guard insist on taking them.
She eventually recovers completely, and goes to Senjumaru's palace with Renji for clothing measurements, in which she and Renji are forced to strip down. After they conclude their business there, they move on to Ichibē Hyōsube's palace to begin training. There, they note the extreme difficulty of moving, with Rukia comparing the Reishi around her to water