I played as Michelle and i 've saved samanosuke & henri. then i got a problem when i played as samanosuke to find saved michelle & henri. when im 've get out from the jail and stand in front of the door, there 's a letter said "it 's locked. michelle and henri must be inside there." i can 't find the key to open that door.
help me, please..

You have to go all the way back to the dome area (entrance of zoo on the left). It's in that room where there is broken glass n' whatnot. There should be a seal that requires Samanosuke's Wind Sword "Kuga", atleast 2 levels upgraded. The key is in there. Oh by the way, that room is the janitorial room.

-Jarred