I've Been Killing Slimes for 300 Years and Maxed Out My Level - Season 1 - Eps 3: Along Came an Elf
Just as peace is beginning to reign in Azusa's home, a young elf named Halkara shows up pleading for her help. Halkara says that an energy drink she made angered a terrifying high demon, Beelzebub, who is now out to kill her. Azusa would prefer to avoid anything that might ruin her slow life, but she can't just leave the poor girl to die, so she reluctantly agrees to shelter her...
About I've Been Killing Slimes for 300 Years and Maxed Out My Level

Title: I've Been Killing Slimes for 300 Years and Maxed Out My Level
First Air Date: 2021-04-10
Last Air Date: 2021-06-26
Status: Returning Series
Rating: 7.9/10 (from 208 votes)
Language: JA
Seasons: 2
Total Episodes: 13
Network: AT-X
Genres: Animation, Comedy, Sci-Fi & Fantasy
Production Companies: REVOROOT, Nippon Columbia, Hakuhodo DY Music & Pictures, SB Creative, BS11, STUDIO MAUSU, AT-X, THE KLOCKWORX, movic, DMM GAMES, Bushiroad, Medicos Entertainment, Square Enix
Synopsis
After dying of overwork in the real world, I’m reincarnated as an immortal witch, and I spend 300 years enjoying a relaxing life. At some point, though, I end up at level 99! All those years spent killing slimes to make the money to pay the bills gave me a ton of experience points. Rumors of the level 99 witch spread, and soon I’m up to my ears in curious adventurers, duelist dragons, and even a monster girl calling me her mom! I’ve never been on an adventure, but I’m the strongest in the world… What’s going to happen to my relaxing life?!