For weeks, Atsushi Nakajima's orphanage has been plagued by a mystical tiger that only he seems to be unaware of. Suspected to be behind the strange incidents, the 18-year-old is abruptly kicked out of the orphanage and left hungry, homeless, and wandering through the city. While starving on a riverbank, Atsushi saves a rather eccentric man named Osamu Dazai from drowning. Whimsical suicide enthusiast and supernatural detective, Dazai has been investigating the same tiger that has been terrorizing the boy. Together with Dazai's partner Doppo Kunikida, they solve the mystery, but its resolution leaves Atsushi in a tight spot. As various odd events take place, Atsushi is coerced into joining their firm of supernatural investigators, taking on unusual cases the police cannot handle, alongside his numerous enigmatic co-workers.

High school student Reki Kyan is passionate about one thing: skateboarding. When night falls, he heads to S, an illegal underground race inside a mine where skaters compete in highly dangerous situations. After a loss that results in his skateboard being destroyed and his arm being broken, Reki is now incapable of practicing at all. While working, Reki runs into his new classmate, Langa Hasegawa, a half-Canadian and half-Japanese boy with no skateboarding experience whatsoever. Langa is in desperate need of money. After they both visit S when tasked by Reki's boss, they get into trouble and are forced into a bet that requires Langa to skate in a race. However, the mysterious transfer student holds a trump card that Reki is unaware of, one which might help him win the race in the most unexpected way.

A new Holy Grail War is emerging in Snowfield, Nevada, where mages from around the world summon Servants, heroic spirits drawn from myth and history, to fight on their behalf. However, this war seems to differ from previous ones. The organization behind it appears to have used data from the Fuyuki Grail War for their ritual, resulting in strange happenings. Unbeknownst to most participants, this budding conflict is actually a fake Grail War. There exists another set of seven true Servants who are summoned to fight in the genuine Holy Grail War. One of these Servants is a powerful Saber-class who saves the life of Ayaka Sajou, his apparent master, after being summoned. With hidden agendas and unpredictable forces at play, the line between the fake and true Grail War becomes unclear, turning Snowfield into a dangerous battlefield.

The young Earl Ciel Phantomhive—the Queen's Guard Dog—is once again called to investigate seemingly supernatural phenomena when news of miraculous resurrections begins to surface in Victorian London. Along with Sebastian Michaelis, his demon butler, they board the luxury cruise liner Campania to investigate rumors of the Aurora Society—a medical organization suspected of experimenting on the dead. Grim reapers begin to appear on the ship, and it becomes apparent that the ship is about to be overrun with the undead as a devious plan is put into motion. Ciel and Sebastian must now uncover the secrets that lie behind the Aurora Society's phoenix symbol, and with the help of some old acquaintances, return the undead to their coffins or share a watery grave.