She got reverse Isekai'd.

Marie is an elf from your usual fantasy setting, but she messed up a teleportation spell and ended up in your house.

Having nowhere else to go, she has been a freeloader for months, and has taken a liking for our world's junk food as well as nerdy hobbies. So she has become a chubby, plump NEET.

But hey, you now have a house elf!

V1.0