The Hero Life of a (Self-Proclaimed) Mediocre Demon! manga volume 4 features story by Shiroichi Amaui with art by Konekoneko.

With Sofia’s kijin safely defeated, the Special Exploration Unit returns to searching for a magical item to undo Chrono’s bonds of domination over Sofia and Yukino. While exploring the tenth king’s dungeon, Lily swallows a glowbug and comes down with an extreme fever that continues to burn hotter and hotter. The only remedy is a magic item known as the Snow Laurel Flower. Akue is determined to cure her best friend, but to retrieve a Snow Laurel, she’d have to dive deep into a frigid dungeon covered in ice and snow. Fortunately, Chrono, along with Sophia and Yukino are more than happy to help!