After some loops, you get the Event Search. If you press X on the setup screen, it will choose options that make a new event likely. Don't manually change the settings if you don't have to, because as long as you used the Event Search only, it will change hidden settings to make the event more likely. If there are events that you can't find, here are some requirements. These hints are based on one or two tries, so there may be additional or unnecessary requirements.

Some events are more likely if the other person trusts you. To make them trust you, defend them, visit them at night and collaborate.