Build the second floor by talking to Ellen. And paying for second floori'm guess the four girls are Lin, Kali, Asheley and Maria... Right?
Viewing post in Harem Hotel (18+) NEW UPDATE! comments
yeah I just haven't figured out how to raise androids levels yet so I assume I need to complete some more events for the other girls first. I got felicity and Emma. Ashley maria lin kali android and the sports girl (Kate?) unlocked so far. And I kinda hope that juliet becomes a character in the future (or if she already is but I'm not at that point yet)