Livestream: Escape from Hotel Izanami

Online streamers Ikoma Mio, Sakurai Nana, and Shiraishi Azusa travel to the locally famous haunted resort, the Hotel Izanami, at Nana's request to shoot a video there.
It would be a film shoot at an average haunted location with no particular legend attached.
To finish shooting without a hitch and get an end result that was vaguely horror-esque...was all they wanted.

During filming, Mio gets separated from the group, and suddenly gets attacked by a mascot costume that has come to life.
From that point on, the trapped girls are at the mercy of numerous horrors throughout the hotel.
Why is a mascot trying to harm them, and why have they been shut in to the hotel with no escape?
Can the three girls escape from the hotel with their lives?

A livestream set in an abandoned hotel begins...

[Edited from Nintendo]