As is traditionally the case in almost every Harvest Moon and Rune Factory game, the official 'Beach Opening' occurs on the 1st day of Summer. Each game celebrates this in a different fashion. In the old Gameboy Friends of Mineral Town/More Friends of Mineral Town, you would enter your dog in a flying saucer/frisbee Contest. In Magical Melody, there was a swimming contest. In Tree of Tranquility, a stone-skipping Mini-Game at the Beach could be unlocked. In a number of Harvest Moon games, the 1st day of Summer was the day when Kai opened his 'Beach Shack' or its equivalent for business for the Summer season. These are only a few examples of Beach Festival Contests.
Often, there are characters who only appear in a specific Season. There were many such characters in Magical Melody. In Island of Happiness, the Mineral Town visitors appear in specific Seasons. In Rune Factory Frontier, it is Bianca and Tabatha from Kardia who arrive on the 1st Day of Summer...
The Beach Festival in Rune Factory Frontier features a 'Melon Pinata' game with some of the eligible girls. Your character is blindfolded and the girls then guide him verbally as he attempts to smash a Watermelon with a Hammer. One girl is designated as a 'liar' to give false directions to make the game more difficult.
The 'Melon Pinata' game is not have as interesting, however, as an optional Event that can be experienced before the Festival begins at 10.00 a.m.
If your character goes to the Beach before 10.00 a.m., it will be quite deserted but, if he attempts to use the changing room, he will suprise one of the Eligible Girls in the act of changing into her bathing costume. Your character, after making his apologies and receiving a warning, can try to enter again, and then will experience a similar event with another girl. Each girl has her own unique responses to your character's actions.
Here is a little video of the Events experienced on the Beach Festival day at the Changing Room:
By the way, for those players who miss the Beach Festival Changing Room Event, it is possible to experience a similar Event on ANY Summer day when the weather is fine by attempting to use the Changing Room between noon and 1.00 p.m.
You may find a different group of girls from those who were in the Changing Room on the day of the Beach Festival as well! On other summer days, there may be as few as three girls in the Changing Room Event as opposed to five. Although Candy will exit the Changing Room a little after 1.00 p.m. with the other girls, she will not be one of the girls that you 'surprise', probably because she remains a child and the implications would be rather ambivalent. Strangely enough, however, if you speak to Candy at the beach on any Summer day, she may randomly turn to you and cry: 'Pervert!' Perhaps it is a reference to the fact that you may have surprised other girls while they were changing on some previous occasion.