When a gate to another world suddenly opens on Earth, Mikado City is invaded by strange creatures known as "Neighbors," malicious beings impervious to traditional weaponry. In response to their arrival, an organization called the Border Defense Agency has been established to combat the Neighbor menace through special weapons called "Triggers." Even though several years have passed after the gate first opened, Neighbors are still a threat and members of Border remain on guard to ensure the safety of the planet. Despite this delicate situation, members-in-training, such as Osamu Mikumo, are not permitted to use their Triggers outside of headquarters. But when the mysterious new student in his class is dragged into a forbidden area by bullies, they are attacked by Neighbors, and Osamu has no choice but to do what he believes is right. Much to his surprise, however, the transfer student Yuuma Kuga makes short work of the aliens, revealing that he is a humanoid Neighbor in disguise. [Written by MAL Rewrite]

The story follows a boy named Quon and others who suddenly wake up with supernatural powers.

Shizuku Mizutani is apathetic towards her classmates, only caring about her grades. However, her cold view of life begins to change when she meets Haru Yoshida, a violent troublemaker who stopped attending class after getting into a fight early in the school year. He is not much different from her, though—he too understands little about human nature and does not have any friends. Much to Shizuku's surprise, he proclaims that she will be his friend and immediately confesses his feelings towards her upon meeting her. Because of her lack of friends and social interaction, Shizuku has a hard time understanding her relationship with Haru. But slowly, their friendship begins to progress, and she discovers that there is more to Haru than violence. She begins to develop feelings for him, but is unsure what kind of emotions she is experiencing. Together, Shizuku and Haru explore the true nature of their relationship and emotions. [Written by MAL Rewrite]

Hikari Hanazono has always been able to do things that normal people cannot. As a child, she assumed no one could beat her—until she met Kei Takishima. Thinking she would win, Hikari challenged him to a match. But things didn’t go as planned; she lost not once but each time she rechallenged him. From that point on, she has sworn to best Kei at everything, ranging from academics to athletics. To achieve her goal, Hikari enrolls in the same school as Kei—Hakusenkan, a prestigious institute for the wealthy. As a pair, they hold the top two rankings in school and are among seven of the academy's best students in a class known as Special A. While Hikari treats Kei as a rival, she is completely oblivious that he harbors hidden feelings for her. Together, the members of Special A deal with competition, friendship, and just a bit of love. [Written by MAL Rewrite]