Slime Taoshite 300-Nen, Shiranai Uchi ni Level Max ni Natteshimatta #13

Slime Taoshite 300-Nen, Shiranai Uchi ni Level Max ni Natteshimatta, widely known in English as I've Been Killing Slimes for 300 Years and Maxed Out My Level, originated as a light novel series written by Kisetsu Morita. The story follows Azusa Aizawa, an office worker who dies from overwork and is reincarnated as an immortal witch, leading a peaceful life until she realizes her daily ritual of defeating low-level slimes has made her the strongest being in the world. The series grew from a web novel published on the Shosetsuka ni Naro platform into a successful print franchise illustrated by Benio.

Volume 13 serves as a later installment in the ongoing light novel series, which remains a staple of the 'slow life' subgenre of isekai fiction. The design and narrative focus on the lighthearted, episodic interactions between the protagonist and her growing found family, a tone that has been consistently maintained across the series' publication history. The light novels are published by SB Creative under their GA Novel imprint, and the success of the volumes has led to various adaptations, including manga and a television anime series.