Byakuya Kuchiki

Do "Byakuya's Cooperation" in free time, or beat him in Bleach tower, Level 9

Gin Ichimaru

Beat him in 5 turns (before Izuru) in Bleach Tower, Level 6

Grimjoww JaggurJaque

Complete floor 30 or Urahada's tower

Hanatarou Yamada

Do "Hanatarou's Cooperation" in free time, or beat him in Bleach Tower, Level 7

Hinamori Momo

Do "Hinamori's Cooperation" in free time, or beat her in Bleach Tower, Level 8

Ikkaku

Defeat him on a one on one fight with your main character In "Ikkaku's cooperation" in free time

Izuru Kira

Do "Izuru's Cooperation" in free time, or beat him in Bleach Tower, Level 6

Kaname Tousen

Beat him in Bleach Tower, Level 12

Kempachi Zeraki

After Recruiting Ikkaku and Yumichika talk to yauchiru in free time afterwards defeat Kempachi in "Kempachi and Yauchiru's cooperation" in free time

Kusaka

Bleach Tower Stage 21. Have Hitsugaya to attack him and complete the stage

Renji Abarai

Do "Renji's Cooperation" in free time, or beat him in Bleach Tower, Level 9

Retsu Unohana

Do "Unohana's Cooperation" In free time, or beat her in Bleach Tower, Level 7

S. G. Yamamato

Do "Yamamato's Cooperation" In free time, or beat him in Bleach Tower, Level 4

Sajin Komamura

Do "Komamura's Cooperation" In free time, or beat him in Bleach Tower, Level 10

Shaolin Fong (Soi Fon)

Do "Soi fon's Cooperation" in free time, or beat her in Bleach Tower, Level 5

Shunsui Kyoraku

Do "Kyoraku's Cooperation" in free time, or beat him in Bleach Tower, Level 11

Shuuhei Hisagi

Do "Hisagi's Cooperation" in free time, or beat him in Bleach Tower, Level 12

Sousuke Aizen

Complete floor 30 of Urahada's tower

Yauchiru

Unlocked with Kempachi

Yoruichi Shihouin (Current)

Do "Yoruichi's Cooperation" in free time, or beat her in Bleach Tower, Level 5

Yoruichi Shihouin (Former)

Beat her in Bleach Tower, in the level she's in with Kisuke Urahara

Yumichika

Unlocked after telling Yumichika he looks like the type to like a fight in "Yumichika's cooperation" in free time