Unlock Kumiko 1+2  -  Use the following password: WsKV7z2

Unlock Kumiko 1+2+3  -  Use the following password: XaoWCBZ

Unlock Saori 1  -  Use the following password: vkz2OBu

Unlock Saori 1+2  -  Use the following password: tYU2TEb

Unlock Saori 1+2+3  -  Use the following password: t9GJ6Ol

Watch Saori's ending  -  Use the following code as your password: t9GJ6Ol

Kumiko 1  -  Use the following password: sMU99R0

Nani 1  -  Use the following password: WQBLD5

Nani 1+2  -  Use the following password: awWl2hx

Nani 1+2+3  -  Use the following password: HtrkwtI

View Saori's ending sequence  -  Enter t9GJ6Ol as a password.
Note: This works for the deluxe version and has three positions.

All possible endings:

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vkz2OBu - Unlock Saori 1
tYU2TEb - Unlock Saori 1+2
sMU99R0 - Unlock Kumiko 1
WsKV7z2 - Unlock Kumiko 1+2
XaoWCBZ - Unlock Kumiko 1+2+3
WQBLD5K - Unlock Nani 1
awWl2hx - Unlock Nani 1+2
HtrkwtI - Unlock Nani 1+2+3
8WgUUD8 - ?
8HNcgZq - ?