Despite the numerous challenges he has overcome so far, Shidou Itsuka's mission with Ratatoskr is far from over. In a departure from his daily routine, Shidou encounters a starving woman lying on the street and ends up helping her. After the two arrive at her apartment, the woman introduces herself as Nia Honjou—a popular manga artist working under a pen name. However, cutting straight to the chase, Nia reveals that she is also a Spirit and is aware of Shidou's secret operation. Interested in seeing his charisma firsthand, Nia challenges Shidou to win her over on a date. As he strives for an opportunity to seal her powers, Shidou learns more about Nia and her history with Deus Ex Machina Industries, a name he is all too familiar with...

In spite of their defeat, the remnant factions of the Taipingtao Revolution continue to resist, plunging China into a seemingly never-ending war. Moreover, the negative emotions left behind by the rebellion's massive death toll begin to form miasma—giving birth to malignant beings called the "wangliang." These creatures can possess humans and turn them into horrifying demons, thus bringing about more deaths and miasma and spinning a vicious cycle that inflicts further despair upon the land. As a countermeasure, the immortal deities known as the "Tianyuan" select certain individuals to be "Hunters." Accompanying them are the "Guizhan," specialists created by the Tianyuan who can absorb miasma and transform into demons themselves, acting as indispensable weapons against the wangliang. After a tragic accident involving an out-of-control Guizhan causes the disbandment of the Sixth Hunter Unit, the Tianyuan designate three promising Hunters—namely Ji Ying, Qiao Xun, and Yan Ding—to reform the group. However, for an unknown reason, the Tianyuan also appoint Xiao Ling—the young Guizhan responsible for the former unit's downfall—to fight alongside the trio. Despite growing tensions, the members of the revived team must settle their differences and collectively use their abilities to attain victory against the common enemy.

As far as it goes, many boys, especially in their teenage years, want to have a girlfriend. Keiki Kiryuu is no exception. One eventful afternoon, his days of yearning for a lover seem to come to an end when he receives a love letter from an anonymous sender—along with a pair of white panties. To determine the identity of his secret admirer, referred to as Cinderella, he proceeds to investigate several possible candidates including his senior Sayuki Tokihara, his underclassman Yuika Koga, and his classmate Mao Nanjou. However, as Keiki seeks to uncover who this mystery girl might be, he comes to know about the perverted fetishes hidden behind each candidate's innocent exteriors...

Shidou Itsuka faces greater peril than ever due to his continued involvement with Ratatoskr. He has already sealed 10 Spirits, and Isaac Westcott, leader of Deus Ex Machina Industries, has finally decided to kill Shidou and plunder the Spirits' powers for himself. To achieve his goal, Isaac declares an all-out war against Ratatoskr, forcing the organization to exhaust its resources to ensure Shidou's survival. Despite being severely outnumbered and outmatched, a glimmer of hope exists in the form of the Spirit of Time, Kurumi Tokisaki. Shidou must seal and acquire Kurumi's power to travel to the past and confront the Spirit of Origin—the catalyst that started it all.