Tucked in the mountains near the elite Kunugigaoka Middle School lies a small derelict building that houses the delinquents and dropouts of Class 3-E. Looked down upon by their peers, the students in this class appear to have little hope in advancing their academic careers. That is, until the national government tasks them with eliminating the greatest threat to their planet: their new teacher. Having already destroyed the moon, the octopus-like professor—dubbed "Koro-sensei"—has now threatened to destroy the Earth by March of the following year. In light of their mission, the students have found that killing him is easier said than done. Not only can Koro-sensei move at speeds of up to Mach 20, but he can also resist almost every earthly weapon. Ironically, he also proves to be one of the best teachers Class 3-E has ever had. Training the class to excel in both their studies as students and skills as assassins, Koro-sensei is confident that his students' ingenuity and indomitable will could return them to the main campus. Through trial and error, Nagisa Shiota, as well as the other students of Class 3-E, must figure out Koro-sensei's weaknesses—and fast, for the very fate of the world depends upon it.

With his parents abroad, Kimihito Kurusu lived a quiet, unremarkable life alone until monster girls came crowding in! This alternate reality presents cutting-edge Japan, the first country to promote the integration of non-human species into society. After the incompetence of interspecies exchange coordinator Agent Smith leaves Kimihito as the homestay caretaker of a Lamia named Miia, the newly-minted "Darling" quickly attracts girls of various breeds, resulting in an ever-growing harem flush with eroticism and attraction. Unfortunately for him and the ladies, sexual interactions between species is forbidden by the Interspecies Exchange Act! The only loophole is through an experimental marriage provision. Kimihito's life becomes fraught with an abundance of creature-specific caveats and sensitive interspecies law as the passionate, affectionate, and lusty women hound his every move, seeking his romantic and sexual affections. With new species often appearing and events materializing out of thin air, where Kimihito and his harem go is anyone's guess!

The first episode of "season" one was pre-aired on the Fate Project New Year's Eve TV Special 2020 program.

Japan, 2019, just before the dawn of a new era. Suddenly, a rift to another dimension appears in the sky, revealing an alternative world "Shinkoku Nippon," with the sky and the earth upside down. This parallel world keeps their former militarism, with its era being Eternal Showa. The military invades the real Japan with giant humanoid robots called "Garann" and their gas weapons "Genmu", rendering our modern weapons ineffective. "Shinkoku Nippon" instantly seizes the government and achieves de facto conquest of Japan. The new era, "Reiwa," has now arrived for Japan. (Source: MAL News)