Jun Eishima was born in 1964 in Fukuoka Prefecture. Her extensive backlist includes stories set in the Final Fantasy, Nier:Automata, and Drakengard universes. Under the name Emi Nagashima, she has also authored The Cat Thief Hinako's Case Files, among other works. In 2016, she received the 69th Mystery Writers of Japan Award (Short Story division), for the title Old Maid.