Here is the full list of all 27 Onechanbara: Bikini Samurai Squad achievements worth 1,000 gamerscore.
Completed Quest No.16 "Swallow's Dance" (LV1~3)
Cleared Story Mode on VIOLENT difficulty
All bonuses for the character "Aya" collected
Completed Quest No.2 "Genocider" (LV1~3)
Completed Quest No.13 "Technical Master" (LV1~3)
Cleared Story Mode on HARD difficulty
Completed Quest No.7 "Dance of the Empress" (LV1~3)
Completed Quest No.8 "Combo Death of the Empress" (LV1~3)
Completed Quest No.17 "Counterstrike Flash" (LV1~3)
Completed Quest No.11 "Cool Master" (LV1~3)
Completed Quest No.19 "Rain of Bullets" (LV1~3)
Completed Quest No.4 "Insane Libido" (LV1~3)
Completed Quest No.3 "Crimson Makeup" (LV1~3)
Completed Quest No.9 "The Untouched Empress" (LV1~3)
Completed Quest No.5 "Near Death High" (LV1~3)
Cleared Story Mode on NORMAL difficulty
Completed Quest No.1 "One Bizarre Woman" (LV1~3)
Completed Quest No.12 "Zombie Piercer" (LV1~3)
Completed Quest No.14 "Height of Ecstasy" (LV1~3)
Completed Quest No.18 "Hit & Run" (LV1~3)
Completed Quest No.6 "Bloody Sword" (LV1~3)
Complete Quest No.10 "Swift and Beautiful Death" (LV1~3)
Complete Quest No.15 "Rampaging Baneful Blood" (LV1~3)
Complete Quest No.20 "Arrival in the Abyss" (LV1~3)
Clear Story Mode on BERSERK difficulty
Collect all bonuses for the character "Saki"
Collect all bonuses for the character "Annna"