Elf Yamada

Yamada Elf is Izumi Masamune's fellow author and neighbor. She is 14 years old.

[Spoiler] Her actual first name is Emily, as she confesses to Masamune during a stroll through the forest that served as the model for the Elven Forest in Emily's debut novel. [/Spoiler]

(Source: Eromanga Wikia)