Tensura Nikki Tensei Shitara Slime Datta Ken

Chapter 38
Vol.4 Chapter 37: Song For The Champions
Chapter 39
Vol.4 Chapter 37: Song For The Champions
Chapter 39
This talks about Rimuru and his friends spending their free time doing something fun together. A spin-off from the main series "That Time I Got Reincarnated as a Slime"