You have to interact with everyone on the map, Jason won't find her. You're probably missing the second room in the club where you find one of the girls sitting, it's around the bottom area of the screen.
This is one of the reasons why point-and-click games suck. This game is a linear story, it should be a VN, not this shit. The game constantly throws you to a map where you have to do things in a specific order to advance the story so it turns into a "find where to click" mini-game every few scenes. And it's not like interacting with other stuff will give you different or even repeatable content, it's just the character going "I have nothing to do here" or "I shouldn't go there". It doesn't seem like the Dev reads the thread but I wish someone would open their eyes to this.
