The Garden of Sinners: A Study in Murder – Part 1 (空の境界 第二章 殺人考察（前）) is a 2007 Japanese animated film produced by ufotable based on The Garden of Sinners novels by Kinoko Nasu. It is the second installment in the series, preceded by Overlooking View (2007) and followed by Remaining Sense of Pain (2008). Chronologically, the events that occur in The Garden of Sinners: A Study in Murder – Part 1 are the first in the timeline of the series.
Plot
In 1995, Mikiya Kokutō briefly encounters a girl named Shiki Ryōgi while walking home. Later on, at his high school, Mikiya recognizes Shiki in a crowd. He introduces himself to her. While Shiki has apparently forgotten their prior meeting and behaves significantly differently, the two become friends. Sometime later, at night, Shiki leaves her home to wander around Mifune City. She finds the corpse of a traffic accident victim and applies their blood to her lips, seemingly in a trance.
The following night, a man is brutally killed by an unseen attacker with a knife. During lunchtime the next day, Mikiya discusses the murder with Shiki, displeasing her. When three more victims are murdered similarly, Mikiya stays with Shiki while she waits for an associate to pick her up from school. They argue when Mikiya inquires about her ignoring the invitation to an upperclassman's farewell party. Shirazumi Lio, the aforementioned upperclassman, also reprimands Shiki cryptically, "I know that you are irritated, but four times is a bit too much, isn't it?"