|Air Date||April 10, 2004|
|Previous episode:||Next episode:|
|Morning of Separation||Aquamarine Melody|
That Horizon is the second episode of Mermaid Melody Pichi Pichi Pitch Pure.
After recieving the phone call and being informed that Kaito is missing, Lucia runs out of Pearl Piari and trips. Hanon, Rina and Hippo ran after her. Lucia said that she was going to look for Kaito, Rina comforted her but said she shouln't try to find Kaito at such a dangerous time like this, especially since there's Mikeru. They were all still wondering who and what Mikeru might be, and they tried to tell Lucia that Kaito is probably okay. Hanon and Rina accompanied Lucia back to Pearl Piari, while Hippo told Momo to help search for Kaito in the sea.
Meanwhile in the ocean, Sheshe and Mimi (Still in their anglerfish forms after the events of Episode 49) were swimming around. Then all of a sudden, Mikeru appeared in front of them and turned them back into water demons.
At night, Lucia is still worried about where Kaito could be, Hippo told her it'd be okay since he told their friends in the sea to look for him. Lucia thanked Hippo, but she was still sad and had brief flashbacks of the moments she and Kaito had together.
The next day, Lucia and Hippo are informed by Momo that none of them were able to find Kaito, so Hippo told Momo to expand the search in a wider area, but Momo told him that something has been bothering them lately. While Hippo was wondering what Momo had told them, Lucia swam off by herself. Hippo quickly ran back to tell the others that Lucia swam away to look for Kaito, so Hanon and Rina had no choice but to look for Lucia in the sea as well.
Lucia was swimming in the sea trying to look for Kaito. Meanwhile, Sheshe and Mimi sent a hypnotized lionfish to lure Lucia away. The lionfish swam near Lucia, she notices that Kaito's Pendant is on the back of the lionfish, so she followed the lionfish, hoping it will lead her to where Kaito is. While Hanon and Rina were swimming to Hawaii, attempting to find Lucia.
Eventually, the lionfish swam inside a cave so Lucia followed it. Outside the cave, Sheshe and Mimi both flirt and laugh with each other that since above the cave is a volcano, Lucia will be buried alive inside once it erupts. Inside the cave, Lucia began to sense that Kaito wasn't really there. Lucia accidentally touched the venomous part of the lionfish and dropped the pendant. When the pendant touched the floor, it turns out the pendant was just an illusion. Lucia felt over due to the poison from the lionfish as the volcano began to erupt. Lucia desperately tries to get up but falls down again.
Suddenly there was bright orange light in front of Lucia, and the light transferred her somewhere else. Once again she saw the orange mermaid that appeared in her dreams, Lucia asked if she was the one making all the bad things happen while the mermaid just replies that she had nothing to do with it, and she heard that Lucia was supposed to protect her. Before the mermaid disappeared again, Lucia asked for her name, the mermaid said that her name was Seira, before fading away.
Lucia was teleported back inside the cave again, she tried to get up and swim out of the cave. But she was only able to swim for a short distance before dropping down to the floor again. She whimpered for Hanon and Rina or Kaito to come and save her. Outside the cave, Sheshe and Mimi were still flaunting about getting their revenge on the mermaids.
Lucia was almost paralyzed on the floor, but then she heard a familiar voice call for name. She recognised that it was Sara's voice. Sara's spirit was in front of her. Sara told her that Kaito was still alive and wouldn't die in the cave since he was the prince of the sea(Panthalassa). Sara revealed to Lucia that Seira is her successor, and that Lucia needs to teach her that love is a wonderful thing. Sara encourage Lucia to escape and to relief her pain by thinking of the battles they have had to ensure the peace of the ocean, then Sara disappeared.
Lucia's body was no longer paralyzed and swam out of the cave with the help of Sara's orange light guiding her, just in time before rocks blocked the exit of the cave. Lucia was relieved to have escaped and thanked Sara. Sheshe and Mimi appeared behind Lucia and mocked her, Lucia was shocked that Sheshe and Mimi were still alive. Sheshe and Mimi continute to flirt with each other in front of Lucia, she was outraged so she transformed into her idol form.
Sheshe and Mimi taunted that Lucia was all alone, then Hanon and Rina appeared and transformed as well. When all three of them gathered in front of Sheshe and Mimi, they sang their new song Yami no Baroque at them. Lucia, Hanon and Rina were almost defeated until Hippo (In his Hippocampus form) crashed Sheshe and Mimi's stage.
The three of them took the chance and transformed into their super idol form and sang Kodou at Sheshe and Mimi. The two sisters were defeated and teleported away as usual. Hanon told Lucia that they were all worried about her and Rina told her to not go alone by herself as it's dangerous.
When they returned back to Pearl Piari, Lucia told them about what happened with Sara and Seira, they were all surprised by the news. Hippo warned all of them that they shouldn't be going to the ocean now cause apparntly it's dangerous.
At the end of the episode, Lucia looks out towards the sea thinking about Kaito while Hanon and Rina watches her.