I've Been Killing Slimes for 300 Years and Maxed Out My Level

After living a painful life as an office worker, Azusa ended her short life by dying from overwork. So when she found herself reincarnated as an undying, unaging witch in a new world, she vows to spend her days stress-free and as pleasantly as possible. She ekes out a living by hunting down the easiest targets—the slimes! But after centuries of doing this simple job, she's ended up with insane powers...how will she maintain her low-key life now?