The Wonderful 101 Remastered: How To Unlock All Secret Characters

All 15 secret characters including Wonder-Captain, Wonder-Scarf, Wonder-Gramps, Wonder-Goggles, Poseman, Wonder-Director, Prince Vorkken, Chewgi, Immorta, Wonder-Daddy, Wonder-Future, Wonder-Red (Emeritus), Bayonetta, Jeanne & Rodin can be unlocked by first completing the game once, by second gaining 6 million O-Parts through gameplay, so that third you can buy each set of characters by entering a cheat code at specific in-game locations. And fourth after unlock each set and actually keep the characters, you must continue playing the level until the game saves, which is indicated on-screen with “Saving” and only then can you exit the level safely.

The cheat code is activated on Switch / Wii U by holding down the ZR button while simultaneously pressing this button combination: Up, Down, Up, Right, Left, X, B, Y, A.
The PS4 cheat code is activated by holding down the R2 button while simultaneously pressing this button combination: Up, Down, Up, Right, Left, Triangle, X, Square, Circle.

The Centinals Set includes: Wonder-Captain, Wonder-Scarf & Wonder-Gramps. Its location is: At the starting position of the Prologue. Price: 1 million O-Parts.
The Real Superheroes Set includes: Wonder-Goggles, Poseman & Wonder-Director. Its location is: In the Epilogue, right after the first car is cut off. Price: 1 million O-Parts.
The Rivals Set includes: Prince Vorkken, Chewgi & Immorta. Its location is: In Operation 009-B, at the starting position of the battle with the shield-generating device. Price: 1 million O-Parts.
The Olden Days Set includes: Wonder-Daddy, Wonder-Future & Wonder-Red (Emeritus). Its location is: In Operation 006-B, during the battle with Laambo, to the west by bowl of noodle soup. Price: 1 million O-Parts.
The Bayonetta Set includes: Bayonetta, Jeanne & Rodin. Its location is: At the start of Operation 001, outside of the school.