Chapter 5

Studyholic (勉強好き, Benkyō Suki) is the 5th chapter of the Parasyte manga series, written and illustrated by Hitoshi Iwaaki.

Overview
''As Migi's intellect continues to grow each day, Shinichi ponders the existence of the Parasites. After heading to school, Migi senses a parasite inside the building. It's revealed that a substitute teacher is the parasite, and she's located Shinichi.''

Summary
Nobuko Izumi welcomes her son as he enters their house and comments on the books he brought home. In his room, Migi emerges to read. Shinichi says it could study for exams for him, but it expresses disinterest in simple memorization. Shinichi then laments that his hand will become smarter than him.

A quick recap of the parasites and Shinichi's life is given, including a flashback of Fujii biting off Toshie Fujii's head. Shinichi ponders on why parasites choose to eat their host species and learns that Migi has no appetite since it subsists off his body's own nutrition.

Shinichi is then called down for dinner and pulls Migi away from its studies. His mother and father discuss the increasing prevalence of the mincemeat murders, and Shinichi once again feels the need to do something about them.

The next morning, Nobuko screams at the sight of a roach, which Shinichi catches in his hand and flings outside. Despite this, Nobuko is still unsettled and complains about his uncharacteristic action to her husband, who assumes it's due to her wealthy upbringing.

Outside, Shinichi meets up with Satomi Murano who praises his basketball game from last chapter, then comments that he's changed again. Shinichi displays nervousness until she tells him he's cheered up.

As they walk Migi sneaks up through the collar of his school uniform and warns him that a parasite is nearby. Shinichi is disbelieving at first, as there haven't been any mincemeat murders around them, until he realizes that the parasite is in his school. Satomi rushes inside, not wanting to be late.

Inside the school gym where the students are assembled, Shinichi looks around for the parasite and Migi determines by process of elimination that it must be a teacher. Migi warns Shinichi not to meet its gaze or it'll find them too. The principal begins to speak, stating that Matsuyama is currently in the hospital and Ryoko Tamiya will be substituting for him. Migi determines that Ryoko is the parasite and, upon hearing that Yamamoto and she will be homeroom teachers for Satomi's class, Shinichi looks up and accidentally catches Ryoko's eyes.