18if is based on a popular mystery puzzle RPG by Mobcast called 18 – Kimi to tsunagaru puzzle, which is currently available on Google play and the App Store.
Akira Nishimori (Episode 1)
Voiced by: Nobunaga Shimazaki
A boy who finds himself in the dream world and is the only person who is able to see a girl named Lily.
He meets the professor, learns of the witches, and gets entangled in various incidents.
Voiced by: Takehito Koyasu
He studies the dream world and is called ‘Professor’ by Haruto. As Haruto can see Lily, he is interested in him and includes him in his research, trying to understand the dream world and the ‘Sleeping Beauty Syndrome.’ Usually he wears a lab coat and sandals, but when he dives in, he takes on the form of a cat.
Voiced by: Kaori Nazuka
She suddenly appears in the dream world and only Haruto can see her. Seeming to appear out of nowhere, she calls Haruto ‘Onii-chan’ and appears only around him.