Yuusuke Yotsuya has always disliked Tokyo, but he especially hates the people who live in it. He would rather thrive in a virtual world than try to get along with those around him. At the end of one school day, he sees the popular athlete Iu Shindou talking to Kusue Hakozaki, who spends less time in school due to illness. But when he looks away from the two and back again, they have seemingly disappeared. Mere moments later, Yotsuya enters a state of free-fall, and the world begins to change around him. Dropping into a large pool of water, the first thing he sees when he comes to his senses is an assortment of enormous monsters. He soon finds out that he has been brought into a game world by Shindou and Hakozaki and that he must complete a quest within 14 days. There is one thing that separates this world from the real world: anyone who dies will be brought back to life in 30 seconds as long as one party member is alive. Tasked with numerous quests that increase in difficulty over time, Yotsuya, Shindou, and Hakozaki attempt to discover the mystery behind the perplexing game world.

Once again, the Game Master's world of quests unexpectedly pulls in Yuusuke Yotsuya and the rest of this old team. Accompanied by the newest addition, Keita Torii, the team reunites with Kahabell, still unaware of their actions' impact on this world. After bidding Kahabell farewell, the team sets out on their newly appointed quest—an offering of a Jiffon Buffalo at Vaikdamnia on Jiffon Island. However, as their journey to the island commences, the team shortly finds that the quest is not as simple as it initially seemed. In fact, the island is terrorized by orcs that have made a deal with its inhabitants: instead of devouring the islanders, the orcs will be granted buffalo. With the growing shortage of buffalo, the annual Vaikdamnia festival cannot proceed. But, given the importance of the team's quest, they are left with the obvious choice—rid the island of the orcs and save the islanders.

Through their tutor Fuutarou Uesugi's diligent guidance, the Nakano quintuplets' academic performance shows signs of improvement, even if their path to graduation is still rocky. However, as they continue to cause various situations that delay any actual tutoring, Fuutarou becomes increasingly involved with their personal lives, further complicating their relationship with each other. On another note, Fuutarou slowly begins to realize the existence of a possible connection between him and the past he believes to have shared with one of the five girls. With everyone's feelings beginning to develop and overlap, will they be able to keep their bond strictly to that of a teacher and his students—or will it mature into something else entirely?

Fuutarou Uesugi's efforts as the Nakano quintuplets' private tutor are finally paying off. The academic performances of the five sisters are steadily improving, and they are each closer than ever to achieving their respective dreams. However, it appears that Fuutarou has become more than a teacher for the girls, who urge him to sort out his feelings. The undecided young man promises to make a decision by the end of the school festival. However, Fuutarou's task will not be easy, as the Nakano sisters pull out all the stops to win his heart before it is too late.