Episode 4

Knock-on effect is the fourth episode of the K anime. It aired on October 25, 2012.

After finally convincing Kuroh to let him prove his innocence, Yashiro Isana starts scavenging around the school's databases for any recorded logs about him that he can use to prove himself. However, he faces several obstacles that prevent him from getting the evidence he needs to use as an alibi. In the meanwhile, both HOMRA and SCEPTER 4 have pinpointed his location at Ashinaka High School.

Summary
The following day, Kuroh prepares lunch for Yashiro, Neko and himself. Neko eats a piece from her bento, unintentionally annoying Kuroh to the point where he tries to catch her with his Aura. At the same time, Yashiro's backpack is picked up by a cleaning robot who, after scanning the Human himself, attempts to dispose of Yashiro as well.

Yashiro then attends class with Kuroh and a transformed Neko accompanying him. The non-students' identities are eventually exposed to the rest of the class, to which Yashiro explains that they are transfer students.

During lunch, while several students are preparing for the festival, Kukuri brings veggie lunches to Yashiro. She finds him eating homemade meals with Kuroh and Neko though, surprising her. As Kukuri shares her lunches with a hungry Neko instead, she notices Yashiro playing around with Kuroh's cell phone; both are researching on the man who shot Tatara Totsuka. Yashiro explains that he was sent the video by his friend, Mishina.

In the meantime, inside SCEPTER 4 headquarters, everyone except for Reisi continues their investigation into Yashiro. The same goes for the members of HOMRA, as Anna is using her abilities to locate Yashiro using a map as a guide. Both Clans discover the white-haired student on Ashinaka High School. Yata immediately darts off to the island after learning of his current location.

Yashiro, Kuroh and Neko dress themselves in Japanese garments to represent historical figures in Japan's history. Yashiro concludes that if he were to find a person who saw him on the school campus within an hour of 11:45 PM on December 7, he'd have an alibi. Kukuri arrives shortly and is asked whether she saw him at the festival that day; however, she states she could not recall him there. This disappoints Yashiro though he continues his search for evidence. He searches around the school, including the student council's office, for any information regarding the events of December 7–8.

After many attempts, he finally gets his proof from the school's database, which shows that he never passed through their gates to exit the school on the day of the festival. Kuroh then decides to accept that Yashiro's innocence. However, it is not long after that Kukuri explains that Yashiro doesn't carry his PDA with him frequently; since a school PDA is required to exit the gate, Yashiro could only sneak out.

Kuroh then proceeds to kill Yashiro for his insincerity. Yashiro continues to resist and lists many other places on the school campus that he could've been during Totsuka's murder. One of them involves Yashiro being in the school gymnasium on December 8. Kukuri does recall seeing him there within the hour of Tatara Totsuka's murder, revealing a photo of him. Kuroh then admits, albeit hesitantly, that Yashiro could not have been the Red Clansman's murderer.

Afterwards, Kuroh decides to help in the production for the school's festival, acting as a motivator for several of the students. In the meantime, Yashiro returns to his room to change, though he notices how he left his uniform. He decides to take a shirt from his closet. He picks up a shirt but before taking it out, notices several red blotches stained on the front: blood. Yashiro realizes that it's the same shirt worn at the time of Totsuka's murder.

Meanwhile, at the school's gate, Yata and Kamamoto arrive to deal with Yashiro. They both attempt to pass through the gates. However, as they did not carry a PDA or a cell phone with which to gain access, they are unable to pass. Both are left confused.

Battles & Events

 * The Truth Shrouded in Secret
 * Infiltration of the School Island