A special gathering has been arranged for a chosen few former high school students to honor their deceased classmate Kiriko, after receiving a letter signed "From K". Ryosuke, a young man with cropped black hair and a past connection to Kiriko, struggles to unravel the mystery surrounding her enigmatic death, unaware of the true identity of "K". While his former classmates suffer horrific fates and his own recollections become clearer, Ryosuke realizes he's running out of time to make things right.
