According to an ancient legend, mermaid's flesh can grant immortality if eaten. 500 years ago, Yuta unknowingly ate a piece of mermaid's flesh. For centuries, he travels across Japan, hoping to find a mermaid, thinking she may be able to make him a normal human again. When he finally finds one, he discovers that she and her companions have been raising a girl to be their food so they can eat her and take on her youthful looks. That is how mermaids stay young. Yuta kills the mermaids and rescues her, but she has already eaten some of the mermaid's flesh. Although he had to kill the mermaids, Yuta isn't too disappointed. Yuta's once lonely existence is now over, as he has found a companion in Mana. And Mana, who had been trapped in a small hut her whole life, finds delight in even the simplest of things. Together, Yuta and Mana attempt to seek out more mermaids, trying to become normal humans again.

How can the hero Fang Han use his own strength to traverse the vast fantastical world? By clinging to an unwavering refusal to accept defeat, he cracked the code of supernatural abilities and transformed his mortal body into an immortal one. Fang Han will reveal a new and prosperous world filled with immortals, demons, and mortals, along with countless innovative magic weapons. In addition, Fang Han will encounter conflicts between immortals and demons, love and hate. It will eventually lead to success.

centers around an imperfect copy of a Grail War based on the Third Holy Grail War in Fuyuki. Following the conclusion of the third Grail War, a US-based organization with magi distinct from the London-based Mage Association, used data from Fuyuki's Grail War to plan their own ritual. Seventy years later, they used the city of Snowfield as the Sacred Land for their own Grail War. However, they were unable to successfully replicate every aspect of the ritual, resulting in it acting only as an imitation that has lost the Saber class and allowed for the summoning of strange Servants due to the blurring of the definition of a "hero." Rohngall and his pupil, Faldeus, have been dispatched by the Mage's Association to investigate the city and the state of the war. Faldeus, a US organization spy, has Rohngall sniped upon his arrival, despite knowing that Rohngall is a puppet. He declares that their Holy Grail War has been in development and is real, causing a commotion at the Clock Tower, and that he wishes to "advertise" the project to the Association.

Eight season of .