A summary of season one of Tensei shitara Slime Datta Ken with some extra content leading into season two.

A futuristic world of a special agent academy ignites the winter of 2017! The secrets of Deep Sea Academy are about to be revealed! Sowing discord! Who exactly is CT17? Betrayal! Did Raya ultimately turn evil? Despair! What happened to Xiu in the end? Destiny! What is the true relationship between Xiaoshuai and Jill? Loyalty! Are Jill and Final just ordinary superiors and subordinates? Negligence! What's going on with Deep Sea security? Jill can freely enter and exit as Leona? Satisfaction! What will happen after Xiaoshuai wins Ling Yixiao's heart? Continue the fight! Today, break through the fog and achieve godhood with a single shot! (Source: Bangumi, translated)

Kings are individuals who have been bestowed with incredible supernatural powers and granted the ability to recruit others into their clans. Protecting the lives and honor of their clansmen is an integral part of the Kings' duties. After a video depicting the heinous murder of a Red Clansman spreads virally, the unassuming student Yashiro Isana is accused of homicide. Now, a manhunt is underway for his head, bringing him into contact with the infamous Black Dog Kurou Yatogami—a skilled swordsman and martial artist determined to follow the wishes of his late master, the Seventh King. Meanwhile, the current Red King, Mikoto Suou, faces his own imminent demise as the search for Yashiro narrows. But during Yashiro's struggle to prove his innocence, a greater conspiracy is unraveling behind the scenes; clouds begin to appear in his memory, and close friends start to question his very existence. What began as a simple murder is now leading towards a full blown war between Kings with the very fate of the world at stake.

Special episodes that take place between episodes 10 & 11 of the TV series.