Once chapter 7 begins, you can search Leanne’s closet as Leanne to use these codes. Press X once, and while her first line is on screen, enter the code. Press X again and she will find the corresponding clothing.
Code – Effect
up up down down left right left right triangle square – 8-bit Girl
triangle triangle up up square square left left L1 R1 – Club Famitsu
R2 L2 L1 R1 Triangle Triangle Triangle square square up – Gemaga
square triangle L1 L1 R1 R1 L3 L3 up down – Hirakou
R2 R1 R3 L3 L1 L2 right left square triangle – Platform Logo
Can Only after getting reindeer suit in Neverland R3 R3 R3 right left triangle square L2 R2 L1 – Politan Suit