Senagaki Isaku will be a first-year high school student starting in spring. Her grandfather is the third head of the Senagaki group, a yakuza organization, so she is feared by those around her. However, starting from spring, she hopes to make normal friends and normally fall in love. She is admitted into a high school further from her hometown, however, the overprotective young head of the Senagaki group, Utou Keiya, (26 years old) falsifies his age and enters the school with her through a backdoor admission…?! Keiya proclaims that love is too early for her although Isaku is perfectly ready. In truth, she has held an unrequited love for Keiya for quite some time.

Iwakura Real Estate, a company that investigates properties marked as "accident properties" with "notices" on the wall, receives a new request. This time, the request is about Room 201 in Urban Heights, where tenants have been moving out one after another due to strange noises being heard. Investigators Mayama Yuto and Shinonome An begin their investigation, but a strange phenomenon is looming over them as well. As they continue their investigation, they discover that the cause of the strange happenings in Room 201 is Room 301 on the floor above. However, when they step into the "unopened Room 301," a frightening truth is revealed...