Eventually, a small task force of Japanese police officers, including Light's father, under the direction of the eccentric genius detective L begin to close in on Light. Although he suspects Light is Kira, L allows him to collaborate with the police on the case. This begins a game of cat and mouse between the two, with Light trying to learn L's real name so he can kill him, and L trying to get Light to expose himself so that he can arrest him. Because the actions of Misa Amane, a fervent Kira supporter and fellow Death Note owner, nearly implicates Light, he becomes compelled to temporarily relinquish ownership of his notebook and subsequently loses his memories of using the Death Note. It is during this time that Light reverts to his original persona: a caring, level-headed, and empathetic individual unwilling to manipulate others or commit or justify acts of crime, such as murder. After Light regains ownership of his notebook and his memories, he manipulates Misa's Shinigami Rem into killing L. Light then assumes the "L" persona and continues his charade of searching for Kira with the task force while carrying out the killings himself with help from Misa.