Eri Nakamura

In the beginning, Eri is portrayed as a calm and quiet girl that loves books. Later on, however, it is shown that she is very cunning and willing to take advantage of classmates for her own personal gain. She has a very deep and deranged obsession for Kouki to the point that she is willing to kill him in order to use 'soul bind' on him and make him her puppet and "boyfriend" forever.