Reiji Andou

Andrei is an obese tall young man, with black hair and pale skin. He has black hair and black eyes. Andrei is heavily covered in mounds of fat and also is the tallest out of the boys, proving himself as the strongest of the five boys during his incarceration in the Prison Block of the school by arm wrestling with the Vice President for five minutes. Andrei has the strangest facial features of any character in the series: his ear lobules reach all the way to the neck below his large head and even though his head is larger than a normal person's head, his face is proportionally smaller than the average teenage boy's face.

The gentle-mannered calm nature of Andrei is shown in his deep care for his friends, often placing them ahead of himself in his relations with them. The care he shows to the other first year boys is especially apparent in his treatment of Jouji Nezu, who he values more than the other boys and shows more emotional concern about. The most lecherous member of the boys, Andrei is also an extreme masochist. The deviant behavior he characterizes throughout the series devolves into more sadistic behavior towards Meiko later on which he refers to as "Andrenomics" or "investment-upon-return".

(Source: Prison School Wiki)