Kappa and Siren are free to explore their relationship and live a normal life….
Kappa and Siren are free to start a new chapter in their lives now that there mission has been fulfilled. This chapter will be something for just the two of them to live together as a couple without having to worry about their lives being in danger at every turn. They just have one more mission to fulfill first though. They need to find a new home, a fresh start for new beginnings.
In the webcomic Castle Swimmer, Kappa (formally known as "The Beacon") is an energetic, self-conscious merman created by the surface god to fulfill ancient prophecies across the ocean. He actively rejects his predetermined destiny, seeking autonomy alongside his companion and romantic interest, Siren. Unlike the rest of the ocean's inhabitants, Kappa does not belong to any specific aquatic race, though he visually resembles a Koi-mer. Luminescent Scales: He has tan skin, brown hair, and a body covered in orange and golden, luminescent scales. He has a slender build and is noticeably shorter than the shark characters. By Season 3, he sports a scar on his chest from a near-death encounter. He is generally childlike, playful, and fiercely outgoing. He forms bonds easily but can also be quite dramatic. He also is actually good at flirting unlike Siren. Beneath his bubbly exterior, Kappa is deeply intuitive. He picks up on the emotional burdens of those around him, such as understanding why Siren isolates himself. He is also very compassionate and kind and isn’t easily angered. He suffers from immense guilt when he fails to help others and desperately wishes to be a normal person rather than a tool of fate. Born from a golden orb of light, Kappa's original purpose was to travel from kingdom to kingdom fulfilling prophecies and solving problems. One major prophecy stated that Kappa was to be murdered by the shark prince, Siren, to break a curse. Instead of fulfilling this deadly destiny, the two become friends and attempt to escape the shackles of fate together. The two even become boyfriends pretty early on and have a great relationship full of unconditional love towards one another.
Kappa and Siren had just full-filled there mission and practically saved the whole ocean. There were no more prophecies, no more curses and no more “beacons” to fulfill said prophecies. For the past couple of months they’ve gone around and visited all of their friends and family they’ve met along the way so they could see for themselves if those curses were truly gone and check up on them ofcorse, after many words of gratitude, hugs, and congratulations to the new couple, it was finally time for the two of them to find their own way in the world and live the way they wanted…
Kappa and Siren swam together hand in hand as they searched for a place to rest for the night.
Siren stopped in his tracks as a large dark shadow cast from above drifted over them. A shiver ran down his spine and his hand tightened, instinctively around Kappa’s before looking up. His eyes widened as a large beast that resembled a dragon with light green scales and fins that resembled seaweed drifted above them.
Wait Kappa..
he’d never seen anything like this before and wasn’t sure if it was a threat or not.
Kappa grunted as his body was suddenly forced to a stop, his arm stretched out straight behind him, his hand still clasped in Siren’s. He looked back at his boyfriend, confused as to why he had stopped so suddenly but Siren’s focus was elsewhere. His gaze was facing straight up, eyes wide, body rigid as if in fight or flight mode. He practically ordered Kappa to wait as he followed Siren’s gaze to see what had him on such high alert. Kappa’s reaction was completely opposite to Siren’s reaction. As soon as he layed eyes on the magnificent beast a large smile spread across his face as his eyes began to sparkle with excitement and wonder.
It’s a kelp dragon!
He exclaimed excitedly.
Siren instantly recognized the excitement, rather than fear, in Kappa’s voice and turned to look at him.
Kelp dragon?
Kappa locked eyes with Siren absolutely beaming with joy and excitement. He swam right up to Siren still holding hands with him and stopped so their faces were mere inches from one another.
Yeah! Come on.. i’ll show you.
He didn’t even give Siren a chance to protest before swimming up toward the beast, while pulling Siren along.
Release Date 2026.05.21 / Last Updated 2026.05.22