The "Boogiepop and Others" novel tells of Manticore, an imperfect clone of the alien entity Echoes, created by the Towa Organization five years later. Escaping the laboratory, Manticore killed Minako Yurihara with the intention of assuming her form when it was found by Masami Saotome. Instead of killing Masami, Manticore struck a deal with him. Manticore (as Minako) and Masami experimented with production of Type S, a highly addictive drug that would enslave all its users to their will, while killing students for Manticore's consumption. Meanwhile, Echoes escaped from the Towa laboratory in chase of Manticore. The alien met up with Nagi Kirima, who was investigating the recent student disappearances.