In the year 2027, the video game Phantasy Star Online 2 is all the rage at Seiga Academy. Every student is on board the fad—except for Itsuki Tachibana, a well-rounded student who doesn't play video games. Due to its popularity, the game is currently under review at Seiga Academy to see if it has a negative impact on the students. Consequently, this causes Itsuki to catch the attention of Rina Izumi, the perfectionist student council president who aims to prove that the game is not to blame. To accomplish her objective, Rina recruits Itsuki as the student council vice president and tasks him with learning to play the game while keeping his grades up. Now obliged to report his daily findings of the game to Rina and analyze its merits, Itsuki carries the fate of Phantasy Star Online 2 in his hands. [Written by MAL Rewrite]

The infidelity of Eita Kidou's parents not only made his family fall apart, but also made him skeptic of love. Having no intention to delve into romance, Eita devotes his entire high school life to his studies in order to become a doctor. It did not take long for the beautiful and popular Masuzu Natsukawa to notice Eita's apathy. Tired of being the object of people's affection, she asks him to pretend to be her boyfriend, as she too feels disgusted at the notion of love. Eita, however, refuses—yet Masuzu has one trick left up her sleeve: Eita’s journal and threatening to post the embarrassing content online if he does not comply. Now entangled in a fake romance with the most desired girl at school, Eita's life is turned upside down. Whether envied by his peers or receiving a confession, he must cope with his newfound relationship and all the troubles that come along with it. [Written by MAL Rewrite]

Naho Takamiya's first day of her sophomore year of high school is off to an uneasy start. After waking up late, she receives a strange letter addressed to her. However, the letter is from herself—10 years in the future! At first, Naho is skeptical of the note; yet, after witnessing several events described to take place, she realizes the letter really is from her 26-year-old self. The note details that Naho's future life is filled with regrets, and she hopes that her younger self can correct the mistakes that were made in the past. The letter also warns her to keep a close eye on the new transfer student, Kakeru Naruse. Naho must be especially careful in making decisions involving him, as Kakeru is not around in the future. With the letter as her guide, Naho now has the power to protect Kakeru before she comes to regret it once more. [Written by MAL Rewrite]

On his way home from school, Tatsumi sees a man collapsed near a lake. When he approaches him, Tatsumi notices something strange: the person in need of help is actually a beautiful merman named Wakasa! Because Wakasa's home has become too polluted to live in, Tatsumi graciously offers his bathtub as a refuge. With a boisterous merman as his new roommate, Tatsumi's normal life won't be returning anytime soon, not to mention Wakasa's aquatic friends—Takasu, Mikuni, and Maki—often show up uninvited, making them all quite a handful for the high school student. As he humors their curiosity for human life, Tatsumi sometimes finds himself enjoying their childish antics, but he will have to keep his cool if he intends to keep up with his daily life and newfound friendship. [Written by MAL Rewrite]