Rukia Kuchiki's zanpakutou spirit.
Sode no Shirayuki first appears in a hidden cave among other Zanpakutō spirits, She tells Haineko they have to wait for the other spirits to awaken when haineko is complaining that she wants to go outside. She is later seen with other spirits attacking soul society.
She is later seen fighting Renji and Rukia, She injures them both but Rukia manages to escape to the real world where she is saved by Ichigo. Soon after Sode no Shirayuki arrives in the real world and attacks Ichigo, the then flees back to soul society after being defeated. After half recovering Rukia sneaks back to soul society, worried about Byakuya. She is yet again attacked by Sode no Shirayuki and easily overpowered. Ichigo shortly arrives and fights her in his Bankai form, holding back because he doesnt want to destroy Rukia's Zanpaktou. He too is defeated.
Rukia then uses Bakudo 61 to restrain them both together, she then uses hado 73 to try and kill them both, to show she cannot live without her and is willing to set her free. Sode no Shirayuki is emotionly touched and has a change of heart and reaches out to her former master who had passed out, however Muramasa then appears in front of her and prevents her from doing so, ordering her to go back to the cave.