The bachelor competition
Even if you have your sights on the bachelor of choice, you might have a rival girl who also has her eye on your man! The rival girls also have a set of events they have to go through before they can marry the boy. Luckily you have control over the triggering of the events. If the girls proceed through their 4 events, the couple will marry 7 days later. The girl might invite you to her wedding that morning, or you can go into Carter's Church to crash the ceremony. You will earn 10 Event points for seeing the rival's wedding.
If you plan to wed Kappa, Won, or the Gourmet, you don't have any rival girls to battle with.
If the bachelor's heart is raised up to the red-level, the rival events will no longer trigger. If you want the other boys to get married and they all have red hearts, you have to wed first to erase the affection they feel for you. After that you can work on triggering the rival events between the girls and the leftover boys.