Oh Seung-Yoon – Triton.

Woo Jung-Shin – Cardia

,Lee Jung-Goo – Eurymedon,

Jung Mi-Sook – Herma,

Jang Gwang – Zeus,

Kang Hee-Sun – Hera,

Yoon So-Ra – Athena,

Sul Young-Bum – Hades,

Hong Sung-Hun – Poseidon,

Yoon Sung-Hye – Amphitrite.

Greek Roman Sinhwa: Olympus Guardian is a spin-off of the TV anime series under the same title.

Greek Roman Sinhwa: Olympus Guardian is a Korean spin-off of the animation series of the same name (신화,  "sinhwa" is Korean for "myths" or "mythology"). The film tells the story of Triton, son of Poseidon, one of the three main Olympian gods (the other two being Zeus and Hades). Poseidon wants his son to learn the art of war so he can defend the world against evil powers. Triton, on the other hand, is convinced that he can defend the world with his greatest talent, which is making friends and helping others. He inherited this trait from his mother, Amphitrite, who is the opposite of Poseidon - she is caring and empathetic. 

Triton's thesis is quickly tested. His mother is kidnapped by a human sorcerer Eurymedon who, using attributes stolen from the chief gods, opens up Tartarus and releases the Titans. All he needs to complete the crime is Poseidon's spear. He appoints a girl, Cardia, to steal it, blackmailing her that he will harm her parents. At the same time, in order to increase his chances of success, Eurymedon kidnaps Triton's mother in order to obtain the desired attribute. Triton and Cardia meet and fall in love with each other, which eventually becomes the reason for the victory over the sorcerer. At the end of the film, the Olympian gods invoke the goddess of victory, Nike, and once again cast the monsters into Tartarus, ultimately defeating Eurymedon.

In this Korean anime, Greek mythology is used in a rather loose way - it provides inspiration for a new story rather than recreates a well-known myth. Towards the end of the film it is even said by one of the sidekick character that the story of Triton has not been recorded anywhere, but is worth knowing. Apart from the main Olympian gods with their attributes (Zeus is the ruler of lightning, Poseidon of the sea, Hades of the Underworld, etc.), there is no recreation of ancient Greek mythological realities here. Eurymedon and Cardia were the names for ancient locations - here, they are inspiration for new characters. Other characters known from mythology are also altered. A great example is Satyr, the little dragon, Triton's sidekick, who most of the time looks and behaves more like Flounder from Disney's The Little Mermaid than the half man, half goat from Greek mythology. Towards the end of the film, Satyr transforms into a huge dragon and becomes the rightful partner of the now mature god Triton, who proved that he possesses great power. 

Greek Roman Sinhwa: Olympus Guardian is one of the many examples of the use of European tradition in East Asian culture. Here, the heroes of Greek mythology resemble elements of Western pop culture rather than characters of ancient heritage. These figures are used as inspiration in numerous anime (e.g., Saint Seiya: The Lost Canvas, Campione!, Kamigami no Asobi). The main theme is the conflict of generations. The older generation of the gods believe in physical strength and are able to sacrifice loved ones for a greater cause. The younger generation believes in the power of the heart and sees saving loved ones as saving the whole world. It is therefore a fairly contemporary theme, although the fact that ancient motifs are used shows their universality and adaptability to all other cultural and historical contexts. 

Maria G. Castello and Carla Scilabra, "Theoi Becoming Kami: Classical Mythology in the Anime World", in Filippo Carla-Uhink and Irene Berti, eds., Ancient Magic and the Supernatural in the Modern Visual and Performing Arts, London: Bloomsbury, 2015.  

Available on DVD in Korea (e.g. http://book.interpark.com/, accessed: August 9, 2021).