Cestina is in a dream, hearing her father's voice calling to her, concerned about her not keeping up with him despite there being little time. She calls out to him, but then she wakes up, calling out the sound "Fa--", before stopping abruptly. Her two brothers wonder what "Fa-" might be, but Cestina, rather than bring up her dream, decides to redirect this new conversation towards her excitement for this vacation. As she steps to the bow of the ship to shout in jubilation, almost the the discomfort of Luahn and Orvell, she privately wonders to herself why she had that dream.
Liza, hearing the commotion, calls out to her siblings, wondering what's going on. She correctly guesses that Cestina is very excited about the Vacation, comparing her to a little kid, while not even trying to hide her own excitement. While talking about Cestina's favorite ice cream shop, the subject turns to one of the legends of the island. Having never heard it before, Luahn asks about the legend. Liza tells him the legend of a rare bird that supposedly links their world with the spirit world. It only appears at sunset, and anyone who sees it can meet with their deceased loved ones.
Luahn assumes this is just some old wives' tale, and Liza admits that there is no proof that the cuckoo even exists. Luahn, while somewhat excited by the prospect of seeing the cuckoo, keeps his expectations realistic. Liza does mention that he might get lucky though, as there is supposedly a sighting every ten years, and they happen to be going to the island around the tenth year since the last sighting. Liza then sees the island on the horizon, and says its name derived from the legend of the cuckoo, for the time it appears between day and night; Twilight Isle.
Finally arriving at the island, the Gran Verge royal siblings prepare for their relaxing tropical vacation. However, Orvell and Luahn soon find themselves in a life and death struggle against an extremely dangerous opponent; Cestina ruling the court in Beach Battleball. She shows no mercy to them, even though Luahn had never played before, and gets carried away in the excitement. She plans on training them for the tournament the next day, but almost winds up breaking her younger brother in the process. Orvell and Cestina then notice that Liza is out of sight and wonder where she might have gone, but Luahn claims to have seen her heading towards a nearby cape in search of something.
Liza searches for something, but finds no sign of it, but then notices a Mikyuon nearby. It jumps onto her, and while she at first is not bothered by it, she then notices a herd of them moments before they also jump on her. Annoyed by this, she throws them off of her, wondering why they did that. Moments later, she gets her answer. A dangerous monster shows itself in front of her, its twin heads looking at her. She wonders how such a dangerous creature is on this peaceful island, but a familiar voice calls out to her, mocking her for being overwhelmed by a bunch of Mikyuon.
Victoire shows herself beside the monster, refusing to tell Liza why she was here. She continues to mock Liza for her audacity to take a vacation despite the chaotic state of affairs everywhere else, alluding to her royal status. Liza defends her family's right for a break, which Victoire notes as being in her rights, and not her problem, as she doesn't actually have time to worry about them. She prepares to leave, although being Victoire, she does get one more insult in, pointing out Liza's "disadvantage" in a swimsuit, setting Liza's temper off.
The monster then starts attacking, putting Liza on the defensive. She notes her disadvantage against these two opponents, especially with her lack of proper equipment, but then realizes she has one more tool in her arsenal. Getting the Mikyuons' attention, she tells them to get in a large magic circle. Victoire questions Liza's plan as the creatures group together in the circle, Liza combines them into one massive Mikyuon. Not expecting this result, both Liza and Victoire just stare at the Mega Mikyuon as it approaches the monster. With no other choice but to se what she has, Liza encourages the Mikyuon and prepares to fight.
Meanwhile, Cestina is searching Liza, wondering if the thing her older sister was looking for might be a feather of the legendary cuckoo that can allow you to meet the dead. This makes her think back to her dream with her father...
Liza, meanwhile, is finding out that while big and silly looking, the Mega Mikyuon is incapable of dealing any actual damage to Garm. Victoire then commands Garm to attack the Mikyuon, breaking it back into a herd of normal-sized Mikyuons. Victoire and the monster prepare to finish them off, but Liza jumps in and warps the Mikyuons and herself away from their opponents, avoiding Garm's wide area attack. Left without her opponents, Victoire is left baffled of Liza's skill with teleportation magic.
Unknown to Victoire, however, was that Liza and the Mikyuons were hidden in a barrier spell, not teleported. Knowing she has to stop Victoire and the monster, Liza weighs her options, coming to the conclusion of using her "magical water gun" to defeat them. By focusing her magic into it, she could deal with either of her opponents, but not both. The Mikyuons she brought with her become noisier and she grows more irritated, making her yell at them, but she's shocked to see there are more with her than she remembered. She then sees for herself how there are so many, as one of them splits into two perfectly healthy Mikyuons right before her eyes (Mitosis?), which she ruthlessly calls "Gross". However, she notes to herself that one of the reasons they can do that is magic, and suddenly has an idea.
Reappearing before Victoire and the monster, Victoire asks Liza if she's ready to fight, to which Liza happily obliges. Victoire is unimpressed by Liza's not very intimidating water gun (making an off-handed remark of its childish nature being perfect for her physique), but Liza undeterred, unleashes her attack. Several Mikyuons appear around Liza, surprising Victoire, as the first Princess starts accumulating their magical energy into one attack, before blasting it (and the Mikyuons!) at Victoire and Garm, overwhelming the monster.
Cestina is now close to the Cape where Liza and Victoire are fighting, wondering why the memory of her father's voice is stuck in her head, and wonders if Liza might also be thinking of their father. Liza, though, is left in the aftermath of her attack, Garm Lying defeated and Victoire still caught off guard by Liza's improvised attack. She prepares to finish Victoire off, when Cestina suddenly yells out to her older sister to stop, tackling her to the ground and interrupting her attack.
Picking themselves back up, Liza asks Cestina why she would stop her from dealing with Victoire's evil plans, only for Cestina to berate her for attacking Victoire. Realizing that Liza was somehow kept out of the loop, she explains that Victoire has been hired by the Kingdom to be the island's caretaker. The reason she is here with Garm is to stop Mikyuon overpopulation, as they have a tendency to infest the entire island, even leading to several interruptions during the previous year's Beach Battleball tournament.
Victoire sarcastically comments that, as an employee of the Kingdom, she might ask for hazard pay, but instead sticks to teasing Liza instead, explaining that she was curious of Liza's actions prior to meeting her at the cape. Cestina is wondering about this herself, and Liza is hesitant to answer, so Victoire just leaves, preparing to enjoy a vacation of her own, seeing as Liza did her work for her. She walks away, bringing an awakened Garm with her, leaving the royal sisters alone. Liza is still irritated with Victoire, but Cestina asks her what Liza was looking for. Liza, though, reveals that she already found what she was looking for...
Somewhere else on the beach, Angelas is excitedly making a sandcastle with some children, when Victoire surprises her. Angelas tries to deflect away from this situation, but Victoire just teases her with the title the Dragon girl got from the children, leading Angelas to note that because Victoire is done with work, she'll go get Eagle so they can get their barbecue dinner started. Victoire, content with her teasing, joins her friends for supper, content.
Reuniting on the beach at sunset, Cestina is glad to see that her brothers trained hard while she was gone, and hopes that Luahn isn't too tired, as he's the only teammate she can join the tournament with due to tournament rules, much to Luahn's chagrin. For a moment, Cestina sees a mysterious bird flying through the air, but no one else sees it. That aside, Liza excitedly claims that the show is about to start. Confused, Cestina asks what this show is, only for magic fireworks to light up the sky. Liza's glad that they work, revealing that they were the reason she was out at the cape, as she needed a place with a natural source of magic to power the fireworks, and the Mikyuon breeding ground was perfect.
Hearing this, Cestina is slightly disapointed, thinking that Liza might have been looking for something else. Liza sees straight through her little sister, and sadly reminds her sister that their father is gone and nothing will change that. However, his memory will remain as long as they remember him, reminiscing of the times they came to Twilight Isle with their father. In particular, Liza remembers how he would bring Cestina with him on the mountain trails, but his pace was so fast she would fall behind, making her cry. Cestina recognizes that this was the memory she had remembered in her dream. Liza admits that she had also had memories of their father pop into her head while she was here, and likens these memories to their father "living on in their hearts".
Agreeing with this sentiment, Cestina remembers the question her father asked in that memory, but knows that she hasn't stopped, and though she may look back, she'll keep moving forward. For a moment, she thinks she hears her father once more, telling her that she doesn't need him to protect her anymore. She looks around for him, calling out, but no one else seems to to have noticed the voice. Choosing not to worry about where the voice came from, she joins her family for barbecue dinner, the first they've had as family in a while.
