Chapter 31

Red Tears (赤い涙, Akai namida) is the 31st chapter of the Parasyte manga series, written and illustrated by Hitoshi Iwaaki.

Overview
''After Kana follows a signal she believes to be Shinichi, she runs into an actual parasite and is fatally wounded. Enraged, Shinichi kills the parasite with his bare hands, and holds Kana as she dies. At her funeral there are two detectives that know the existence of the parasites and have interrogated Shinichi. After briefly fighting Mitsuo, Shinichi begins hitting his head against a tree, and is relieved to see that his blood is still red.''

Summary
Unable to contact Kana, Shinichi wonders where she would head to. He tells Migi that she claimed to be able to tell them apart from normal parasites, to which Migi states even regular parasites have a hard time distinguishing each other. Shinichi decides to try Kana again in lieu of heading out where he might miss her.

Kana picks up a parasite signal and begins to trail it.

Shinichi starts to head in the direction of her house. He tries to detect her by his hearing, but is unable to discern it in the rest of the environment's noise, and asks Migi if he can sense her. He doesn't, stating that she might not even be emitting now, but he does sense another parasite that she might have decided to head towards. Shinichi immediately goes towards it.

Having found the signal in the place she spoke with Shinichi earlier, Kana decides that he must have come here deliberately, and walks on a parasite feeding on a human. She tries to run and the parasite stabs her through the chest. As she dies she has a flashback of her dream, while Shinichi arrives just in time to see her collapsed.

Anguished, Shinichi tells Migi to protect him and charges in, letting Migi block the parasite's blades while he slams his left hand into the parasite's chest, tearing its heart out and flinging it into a wall. Migi is impressed.

Shinichi then holds Kana as she fades away, with her reminiscing about the dream of Shinichi as her savior. He spots the place where she had begun writing his and her name together.

Kana's funeral takes place, a pair of detectives talking about Kana's death, the new parasite sample and Shinichi as well as his mother's death by parasite. Mita comments on Shinichi's unfriendly demeanor towards them, and Hirama wonders what had killed the parasite that killed Kana, guessing it to be another parasite. He reveals that Shinichi stated he didn't witness anything.

Away from the funeral, Shinichi blames himself for calling Kana that day, while Migi tells him it was only a matter of time once she began sending signals out. Mitsuo then comes up to him and begins to attack him, angry that he didn't protect her and that he doesn't cry for her. Mitsuo then calls him inhuman, stating that he doesn't cry or bleed. Shinichi starts attacking him back for the comment, then stops and leaves. He wonders to himself why he's calm, then worries that Migi has taken over his brain without him even realizing because he can't cry. He slams his head into a tree and is stopped by Migi. He expresses relief that his blood is still red.