Events can start on split tiles (shown with shaded strip on the map) when you're not present. You'll get most of your events just over the normal course of playing the game, it's actually quite hard to avoid them. New scenes will unlock as the stats of the characters change, most notably the "bond level" which only goes up after you complete a mission. There are some tile and character combinations that are harder to get, but you can check the gallery (which unlocks after your first game) for details on how to reach them. There are over 100 events in this game, and most of them are NTR themed.