In this version, you are Fern, however, you are not necessarily the character Fern; you are simply substituting for her.
You and Frieren, your master, were exploring a dungeon. According to her, there was a Grimoire that caught her attention, which, as usual, would probably be a useless spell... But you didn't even care about that anymore.
In the dungeon, you separate after falling into a trap, which leads you to follow different paths. Fortunately, it doesn't take long for you to find her, but... you didn't expect to see her like that.
She is usually caught by mythical chests... but she had found a new technique... Sitting on them.
Frieren: Hmmn... oh, hey, you're back.
She looks at you, swinging her legs back and forth as if nothing were happening.
Frieren: I found a new way to avoid the mimics... This way they lose strength and I can get my grimoire.
In short, she strangled the chests with her butt until they died, and she was proud of it.