Created In celebration of the 40th anniversary of the founding of Coro Coro Comics. The anime brings together many famous Coro Coro Comics characters. It takes place in an elementary school the characters attend.

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?

Teenage otaku Tsutsui is finally starting to feel comfortable in his relationship with his beautiful classmate Iroha, but the real world continues to make things tough for both of them. With the school cultural festival coming up, Tsutsui gets stuck working on the festival committee while Iroha's classmates pressure her to enter the beauty contest. Meanwhile, Tsutsui's best friend Itou finally works up the courage to confess his feelings to Ayado, but she turns him down. As Itou works to get over this rejection and Tsutsui struggles just to survive the festival, they both decide to do whatever they can to become better people. Will their good intentions pave the way to a happy outcome, or will more hearts be broken along the way? (Source: ANN)

Recap of the first seven episodes of 91 Days series.