Tensei Shitara Slime Datta Ken: Kanwa - Veldora Nikki

 The first OVA of That Time I got Reincarnated as a Slime, Veldora Nikki tells the first season, with a twist.

Because it is viewed from the stomach of Rimuru, where Veldora and Ifrit are stored, and playing a game of Shogi.

During the time they spend playing, Veldora recounts the story of what happened to Ifrit, and the viewers.  However, the way this recap is brought makes it funnier then most recap episodes, as they have some good mannered, but fun, banter going on between them two.

It's nothing spectacular per se, but a nice recap if you are preparing for the second season.