In 1863, Izuminokami Kanesada and his partner, Horikawa Kunihiro, arrive in the streets of Edo from the future to investigate their master's reports of an upcoming enemy invasion. As humanoid manifestations of the famous Toshizou Hijikata's swords, they have been tasked with protecting history from the Retrograde Army that seeks to alter it. Soon enlisting the help of other sword warriors, they continuously battle the mysterious army throughout the Bakumatsu period. However, their journey will not be an easy one. Fraught with blood and betrayal in the chaotic era closest to their hearts, the duo will be forced to make difficult decisions with everything they care about on the line. [Written by MAL Rewrite]

A 5000-year-old vegan dragon was living peacefully when one day a young girl showed up in his cave. She offered herself as a sacrifice in order to gain favor for her village. He played along as the great "Evil Dragon, the Demon Lord's Army Leader" in order to get rid of her. However, his little white lie awoke her hidden powers and his peaceful life suddenly ended.

Rika Furude and her group of friends live in the small mountain village of Hinamizawa; in June 1983, they welcome transfer student Keiichi Maebara into their ranks, making him the only boy in their group. After school, they have fun playing games and spending each day living their lives to the fullest. Despite this seemingly normal routine, Keiichi begins noticing strange behavior from his friends, who seem to be hiding the town's dark secrets from him. Elsewhere, a certain person watches these increasingly unsettling events unfold and remembers all the times that this, and other similar stories, have played out. Using that knowledge, this person decides to fix these broken worlds. However, when certain variables change, the individual is faced with a horrifying realization: they have no idea what to expect or how to stop the impending tragedy. [Written by MAL Rewrite]

The world has become a slaughtering ground for the Crimson Denizens, mysterious beings from a parallel universe who thrive on the life energy of humans. These merciless murderers only leave behind scant remainders of souls called "Torches," which are mere residues that will eventually be destroyed, along with the very fact of the victims' existence from the minds of the living. In an ambitious endeavor to put an end to this invisible, hungry massacre, warriors called Flame Hazes relentlessly fight these monsters. One fateful day, Yuuji Sakai ceases to be a regular high schooler—he becomes trapped in a crevice of time and is suddenly attacked by a Denizen. Coming to his rescue just in the nick of time is a nameless hunter who seems no different from an ordinary young girl except for her blazing eyes and burning crimson hair. However, before Yuuji can learn anything more about his situation, he discovers that he has already been reduced to a Torch—merely a scrap of memory waiting to be extinguished. [Written by MAL Rewrite]