"Reel in the Guardian's Tower!?" In a world strikingly similar to the VR game "Ria Deil," the high elf "Kena," also known as Kakami Keina, has been living a lively yet peaceful life with her new adopted daughter Luka and the villagers. One day, Kena decides to take Luka to meet her eldest daughter, Maimai, and sets off once again to Felskeiro, accompanied by the innkeeper's daughter Ritt and the maid Roxine. Despite being attacked by thieves, Kena and her companions arrive safely. Upon their arrival, Kena receives a message from a guardian in the form of smoke, requesting her help to save the "Guardian's Tower," which is on the verge of running out of MP necessary for its maintenance. To her surprise, this "Guardian's Tower" is a massive, over 100-meter-long blue whale that moves underwater! Kena begins to devise a plan to reel in the tower...! The fourth installment of the elf legend that begins 200 years later!