Kobayashi-san Chi no Maid Dragon

Programmer Kobayashi opens her door one morning to find an enormous dragon waiting outside, only for it to transform into a girl named Tohru dressed as a maid. Kobayashi slowly remembers meeting her in the mountains while drunk, removing a sword lodged in her body, and casually offering her a place to stay without expecting the dragon to accept. Tohru enters her life with enthusiasm far greater than her understanding of human housekeeping, and other dragons soon follow, beginning with the young Kanna. What was once a quiet apartment for someone who mostly lived to work gradually becomes a strange, noisy household warmer than anything Kobayashi has known in years.