Fumiya Tomozaki is now cruising through the game of life—all thanks to the guidance of Aoi Hinami, his popular classmate and rival in the online game Attack Families, widely known as Tackfam. As the summer holiday draws to a close and a new term commences, Tomozaki reunites with Aoi, who reminds him of his ultimate goals: to become well-liked among his peers and find himself a girlfriend. However, Tomozaki puts his ambitions on hold when his innocent friend, Hanabi Natsubayashi, starts being bullied. To make matters worse, Aoi is characteristically out of touch with the situation. But Tomozaki is not alone in resolving this issue—he now has a group of loyal friends who are all determined to help Hanabi and ensure they enjoy their youths together to the fullest.

In a war against four overpowered races—angels, demons, undeads, and humanoid beasts—humanity could only prevail thanks to its champion Sid, who defeated the other races' champions and sealed away their armies in four pyramids. In an age where Sid's existence has become but a legend of the past, Kai Sakura Vento is one of the many conscripts tasked with monitoring the pyramids in fear that these old foes would escape. On a peaceful day while spending time with his friend Jeanne E. Anise, the world is suddenly overwritten, transporting Kai to an alternate reality where humanity has nearly been annihilated by the demons and forced into hiding. To make matters worse, his very existence has been erased from this world; all of his friends, including Jeanne, who leads the local resistance efforts in this world, have forgotten about him. Trying to investigate the remains of his former world, Kai encounters Rinne, an enigmatic young woman trapped in a pyramid. Mysteriously inheriting Sid's legendary sword Codeholder, Kai manages to free Rinne from her imprisonment. Determined to fix this reality, Kai joins forces with Rinne and Jeanne to free humanity from demonic rule. But if the valiant soldier wants to have a chance at returning to his original world, he will first have to uncover the cause behind the mysterious alteration of reality.

When regular salaryman Yoshida wakes up one Sunday morning after a long night at the bar, the last thing he expects to see is that his tiny apartment has a new resident—an unfamiliar high school girl. The previous night, despite finally gathering the courage to confess to his boss and longtime crush, Airi Gotou, Yoshida was rejected. After drowning his sorrows at a bar with his good friend Hashimoto, Yoshida headed back to his home in a drunken stupor, only to run into Sayu Ogiwara, a runaway high schooler. She asked him to let her stay the night, and with his judgment clouded by alcohol, Yoshida complied. Now, with his head on straight but with no memory of last night's events, Yoshida has Sayu explain just how she ended up sleeping at his apartment. Having listened to her story, Yoshida finds himself unable to kick her out—especially after learning that she came all the way from Hokkaido! So, despite his reservations about sheltering an underage girl, Yoshida allows her to stay, and their life together begins.

Fumiya Tomozaki is Japan's best player in the online game Attack Families, commonly known as Tackfam. Despite holding such a revered title, a lack of social skills and amiability causes him to fall short in his everyday high school life. Failing to have any friends, he blames the convoluted mechanics and unfair rules of life, forcing him to give up and proclaim himself a bottom-tier character in this game. After a fateful meeting with another top-tier Tackfam player, Fumiya is shocked to discover the player's true identity—Aoi Hinami, a popular, smart, and sociable classmate who is the complete opposite of himself. Aoi, surprised at how inept Fumiya is at everything besides Tackfam, decides to assist him in succeeding in what she calls the greatest game of them all. Through the gruesome ordeals of social interactions and relationships, Fumiya begins to advance tiers in the glorious game of life.