is a Japanese manga series written and illustrated by Yukito Kishiro. It's a tale about Ruliya, a female orca-riding knight, making an epic journey through the aqueous world of Marmundo. After publishing three volumes, Kishiro placed the series on hiatus to draw Battle Angel Alita: Last Order. He has promised to continue Aqua Knight when that is finished. Story In the first volume, Lady Ruliya, a young knight in training, becomes lost during a storm and sinks in her submersible armor. A young boy, Ashika, saves her with the help of his father, Arrabarus. She finds herself on the lighthouse island they guard, far away from civilization. As thanks for his help, Ruliya promises Ashika anything, but she immediately regrets it as Ashika wants to become a knight as her. She is a woman of her word and shows her skill as a knight in fighting Arrabarus, who turns out to be an old aqua knight. However, the duel is interrupted by the travelling genius Alcantara in his flying fortress. He steals the lighthouse's light sphere, which Ashika calls Niselle and claims is his mother. In the ensuing battle, the lighthouse is destroyed and by some mysterious connection this kills Arrabarus. Ashika is also kidnapped. Tagmec, knight of the Underworld, emerges from the sea to claim the old man, but not before Ruliya promises to rescue the boy and the light. Tagmec informs her she is embarking on a quest of destiny. He grants her Muertogara, a magical blade, for this purpose. In volume two, more is seen of the eccentric Alcantara, his wondrous inventions and his crew, and see how Ashika endures his captivity. Meanwhile, Ruliya pursues them on her orca mount, but comes across a mysterious knight who invites her to his castle in the middle of the sea. He turns out to be a demon knight who is after both Ruliya and her magic sword. Despite his tricks and charms, Ruliya defeats him. Pinoque, a fairy friend from her childhood, returns to her to aid in her quest, and she sets out after Ashika and the light sphere with renewed purpose. Volume three tells the story of Alcantara, his history in the far-away land of Zygote and his quest in Marmundo. Through a flashback, we learn how he became the greatest genius in Zygote, but was forced to flee because of his unorthodox ideas and dangerous experiments.