Secret Library

Secret Library (図書室の秘密) is a short story in the manga anthology Neo Parasyte F, written and illustrated by Hajime Shinjo. It is Case 13 in the volume.

Synopsis
A schoolgirl named Hinako Ono is discomfited by the new transfer student, Shinobu Arai, whose handsome face and composed attitude are praised by the rest of the girls. The truth is, she saw something monstrous growing on his back in the library, and will do anything to avoid being alone with him. Unfortunately, the "thing" doesn't take being witnessed well.

Summary
Hinako chats with her friends as she arrives to school, and as they discuss their after-school plans she is reminded of her afterschool cleanup duty with her assigned partner, transfer student Arai Shinobu, who is widely admired though Hinako herself is unnerved by him. They chat about the rumored tragedy of his parents being killed by a mincemeat murderer. Hinako approaches him herself and comments on his large appetite, then tries to convince him to head home and let her do all the chores herself.

However, after school he shows up anyway to do his part and causes Hinako to rush her work in fear. Arai then asks if she dislikes him, and she has a flashback to seeing a parasite growing out of his back and reading a book in the library. In return she asks if he can think of any reason, then hurriedly backtracks. Instead of letting her leave, he asks what she saw. She tells him the truth. Behind him, the parasite begins to cut through his clothes and attempts to attack her. Shinobu manages to deflect them in time, but Hinako escapes. He berates his parasite, Sally, and tells it they will never kill people again. He then chases after Hinako as Sally tells him another parasite is near her.

In a small police station, Hinako tells the officer about the monster, only to hear him reveal that he's one as well. He begins to transform, but is himself killed by Sally before he can attack her. Hinako faints onto Shinobu.

She eventually wakes on a park bench with him watching over her and is nearly frightened away again by Sally. However, Shinobu manages to stop her and explain that his father had actually killed his mother and nearly killed him as well, only stopped when Sally took over his back and killed the man instead. He still feels guilt for the murder, though Sally tells him that only itself had committed the crime.

After some contemplation on Shinobu's self-guilt and questions to Sally, Hinako finally declares that she's glad he's alive because he saved her life. Sally ruins the moment by pointing out she wouldn't have gone to the police parasite if she'd never met him in the first place. Ignoring Sally, Hinako invites Shinobu for ice cream after school and hopes he will smile for real one day.

Characters

 * Hinako Ono
 * Shinobu Arai
 * Sally (Parasite)