Devil's Drink

The local bar.

Drinking here
You can drink here for $7. It gives you the Tipsy status effect.

The secret arena
Once all-knowing-hobo tells you about the arena, you can approach the barman and tell him the code phrase. If done correctly, they would allow you to go through the back room, accessing the underground arena.

Once you talk to the organizer, you can access the arena at any time. You would always face one of the following enemies:
 * Highwayman
 * Bandit Girl
 * Wildcat
 * Lin-Lin (rarely)

They never drop any loot, and have no post-defeat scenes; the only enemy to have post-victory scene is Lin-Lin, if defeated through lust.

You receive $100 for each enemy defeated (including Lin-Lin). There's no upper limit how many you can face, and you can't be reduced below 1 point of stamina, so if you can defeat your enemies before they defeat you, you can continue fighting even beyond that.

There's no penalty for losing a fight, but Lust Doll was defeated with high arousal, they would be forced to publicly masturbate.