How to Keep a Mummy ( Air Date 2018-01-12 ) Genre Animation, Comedy, Sci-Fi & Fantasy category. Overview "When high school student Sora Kashiwagi finds himself staring down a mysterious oversized package sent to him by his self-proclaimed "adventurer" father, the last thing he expects is for it to be opened from the inside... by a little mummy so small it can fit in the palm of his hand!".