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you are missing the 3rd requirement, you can easily check this:

there are 2 npc's in the dev room next to the "exit" teleporter
if no one is there, you simply missing the last requirement
if there are 3 npc's next to the teleporter than you already unlocked katana-tan

the 3rd requirement is to play through the game without activating an erotic event, it can be done in ng, ng+ or curse mode. Imortant is, in the sanctuary, you have to use the teleporter twice.