War(Date), resumes. The peaceful days of Itsuka Shidou returned without having to save the Spirits from the relentless battle days. But, the peaceful days were interrupted by the emergence of a mysterious sphere emitting spiritual wave――as well as a mysterious girl who showed herself at the same time. What is her purpose of keeping an eye on Shidou……? The mission that had been entrusted to Shidou under the tense situation was, “Date all of the Spirits, and make them fall in love?!” ――With the fate of humanity at stake, the war(date) resumes! (Source: Date A Live Wiki)

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...

Shidou Itsuka carries on with his quest for Ratatoskr in finding Spirits and trying to seal their powers, all while maintaining his relationships with the ones he had already sealed. Moreover, as new Spirits appear, he must undergo more complicated trials—all to put a stop to further disasters as he discovers more about the Spirits' origin.

Thirty years ago, the Eurasian continent was devastated by a supermassive spatial quake—a phenomenon involving space vibrations of unknown origin—resulting in the deaths of over 150 million people. Since then, these quakes have been plaguing the world intermittently, albeit on a lighter scale. Shidou Itsuka is a seemingly average high school student who lives with his younger sister, Kotori. When an imminent spatial quake threatens the safety of Tengu City, he rushes to save her, only to be caught in the resulting eruption. He discovers a mysterious girl at its source, who is revealed to be a Spirit, an otherworldly entity whose appearance triggers a spatial quake. Soon after, he becomes embroiled in a skirmish between the girl and the Anti-Spirit Team, a ruthless strike force with the goal of annihilating Spirits. However, there is a third party that believes in saving the spirits: Ratatoskr, which surprisingly is commanded by Shidou's little sister! Kotori forcibly recruits Shidou after the clash, presenting to him an alternative method of dealing with the danger posed by the Spirits—make them fall in love with him. Now, the fate of the world rests on his dating prowess, as he seeks out Spirits in order to charm them.