It doesn't matter if you like Ais or not, by picking "I like Ais" at the beginning you take the common route where the Brothel location is unlocked. It doesn't get unlocked right away since Bell won't just wake up a morning and be like "Let's slay some Amazons with my secondary dagger!", but it'll get unlocked around the time he gets his first spell and learns about Mind Down status, so much later in the story.