Spirits are otherworldly entities with immense power, capable of creating spatial quakes whenever they appear. One way of dealing with them is through brute force and killing them... or making them fall in love and sealing their powers. Having sealed three Spirits, Shidou Itsuka continues his mission with Ratatoskr in locating more spirits and dating them, to ensure the world's safety from further destruction. However, this time around, their problems will not be limited to Spirits as a more imposing threat seems to have noticed their activities. [Written by MAL Rewrite]

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. [Written by MAL Rewrite]

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. [Written by MAL Rewrite]

Lucy is a special breed of human referred to as "Diclonius," born with a short pair of horns and invisible telekinetic hands that lands her as a victim of inhumane scientific experimentation by the government. However, once circumstances present her an opportunity to escape, Lucy, corrupted by the confinement and torture, unleashes a torrent of bloodshed as she escapes her captors. During her breakout, she receives a crippling head injury that leaves her with a split personality: someone with the mentality of a harmless child possessing limited speech capacity. In this state of instability, she stumbles upon two college students, Kouta and his cousin Yuka, who unknowingly take an injured fugitive into their care, unaware of her murderous tendencies. This act of kindness will change their lives, as they soon find themselves dragged into the shadowy world of government secrecy and conspiracy. [Written by MAL Rewrite]