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.

Not long after forming their partnership, detectives Ron Kamonohashi and Totomaru Isshiki have proven adept at solving various cases together. However, the two are further motivated to continue their work when they discover that the House of M—an infamous crime syndicate—orchestrated Ron's expulsion from the prestigious Detective Training Academy BLUE five years prior. It appears that this group is also linked to Ron's mysterious ability that causes those around him to lose their lives, a phenomenon which Ron is desperate to stop. A member of the House of M soon starts to commit boastful serial murders around Shibuya as an act of provocation toward Ron. Consequently, the investigative pair must do their best to apprehend the culprit for the sake of justice as well as learning more about Ron's dark past and present condition.

On the 20th floor of the Tower, the "Regulars" who have been permitted to enter have to undertake arduous and extremely expensive tests to rank up. Most abandon hope and choose to stay where they are—but not Ja Wangnan. Wangnan is determined to reach the top and become the king of the Tower. However, he is weak and has repeatedly failed the exam, with debt collectors tailing him. In desperation, he attempts the exam one more time, only to encounter a mysterious and powerful individual: Jyu Viole Grace, a member of the crime syndicate FUG. Cursing his rotten luck, Wangnan has no choice but to form alliances with strong people, including Viole—who still refuses to be part of any team. Amid a dire situation, Wangnan must find a way to change Viole's mind to finally advance past the 20th floor, or he will never get a chance to build his legacy.