I don't know if a particular outfit is required, but no, nothing in particular.
Viewing post in I'm stuck
Why did you mentioning Jun's outfit?
Jun has nothing to do with this event.
If you already used the Lingerie Catalogue, it should trigger when you go for a walk outside alone between 02:00 - 02:59 AM.
If it's not triggering, maybe it's because there are some other event going on. For example, the Riot event.