At the start of her freshman year in college, Hana Uzaki reunites with Shinichi Sakurai, an upperclassman who was in the same club as her during her high school days. However, much to her surprise, the once active senior has ended up becoming a lonesome student, preferring to spend his free time in quiet peace. Uzaki does whatever she can to keep Sakurai from being alone, from convincing him to go to the movies to going to his part-time workplace. While Sakurai finds her irritating and tiresome, he still goes along with Uzaki's hijinks and shenanigans, even if he knows that her perky personality will only lead the two of them into various comical situations. Even so, as the days pass by, their relationship only gets better, to the point where people around them misinterpret them to be a couple. At any rate, whenever Uzaki wants to hang out with her upperclassman, fun and adorable wackiness is sure to follow!

While reveling in the successful clinching of a prized vase for his collection, Yoshifumi Nitta, a yakuza member, is rudely interrupted when a large, peculiar capsule suddenly materializes and falls on his head. He opens the capsule to reveal a young, blue-haired girl, who doesn't divulge anything about herself but her name—Hina—and the fact that she possesses immense powers. As if things couldn't get any worse, she loses control and unleashes an explosion if her powers remain unused. Faced with no other choice, Nitta finds himself becoming her caregiver. To let her use her powers freely, Nitta asks Hina to help out with a construction deal, which goes smoothly. But while this is happening, a rival yakuza group covertly attacks his boss. To Nitta's shock, his colleagues later pin the blame on him! Tasked with attacking the rival group in retaliation, Nitta steels himself and arrives at their hideout. But suddenly, Hina unexpectedly steps in and helps him wipe out the entire group. As it turns out, Hina might just become a valuable asset to Nitta and his yakuza business, provided she does not use her powers on him first! And so the strange life of this unusual duo begins.

Most people would prefer being the protagonist of a world full of adventure, be it in a game or in another world. But, unfortunately, a certain girl is not so lucky. Regaining the memories of her past life, she realizes that she was reborn in the world of Fortune Lover—one of the games she used to play. Unfortunately, the character she was reincarnated into—Catarina Claes—is the game's main antagonist, who faces utter doom in every ending. Using her extensive knowledge of the game, she takes it upon herself to escape from the chains of this accursed destiny. However, this will not be an easy feat, especially since she needs to be cautious as to not set off death flags that may speed up the impending doom she is trying to avoid. Even so, to make a change that will affect the lives of everyone around her, she strives—not as the heroine—but as the villainess.

After an exciting and momentous cultural festival, Shouko Komi continues her endeavor to make one hundred friends alongside her friend and classmate Hitohito Tadano. As winter begins, the class is joined by the seemingly delinquent student Makoto Katai, who has been absent since the first week of school. Despite his intimidating appearance, Katai has difficulty communicating with others and just wants to befriend his classmates. As new friendships form and current ones deepen, Komi and Tadano’s relationship begins to change—though not necessarily for the worse.