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

Ifrit, who has been trapped in Rimuru due to the latter's Predator skill, recaps events of the season while in a discussion with Veldora as they play Shogi.

The world of Duel Monsters is once again evolving with the development of a network called Link Vrains and a new summoning mechanic introduced as Link Summoning. By using this cyberspace, duelists can now create their own avatars and duel their way to glory within a virtual reality. However, much like the real world, the digital world is not free from war, conflict, and mysteries. Years ago, a hacker organization known as the Knights of Hanoi unleashed an attack on Link Vrains. Led by the anonymous Revolver, their aim was to annihilate the artificial intelligence program known as the Cyberse. After a failed attempt, one of their targets, Ignis, managed to escape and hide the Cyberse somewhere in the network. Five years later, high school student Yuusaku Fujiki encounters a strange artificial intelligence program while dueling in Link Vrains. Under the guise of his avatar named Playmaker, Yuusaku and his partner in crime, Shouichi Kusanagi, decide to join forces with the peculiar existence. As he seeks the truth behind a mysterious incident of the past, Yuusaku battles against the Knights of Hanoi and SOL Technologies in a race that might alter the fate of the world.

As far as it goes, many boys, especially in their teenage years, want to have a girlfriend. Keiki Kiryuu is no exception. One eventful afternoon, his days of yearning for a lover seem to come to an end when he receives a love letter from an anonymous sender—along with a pair of white panties. To determine the identity of his secret admirer, referred to as Cinderella, he proceeds to investigate several possible candidates including his senior Sayuki Tokihara, his underclassman Yuika Koga, and his classmate Mao Nanjou. However, as Keiki seeks to uncover who this mystery girl might be, he comes to know about the perverted fetishes hidden behind each candidate's innocent exteriors... [Written by MAL Rewrite]