Switch

is a shōnen, action manga series written by Otoh Saki and illustrated by Tomomi Nakamura. It was serialized in Square Enix's GFantasy from 2002 to October 2008. The individual chapters were collected and published in 13 tankōbon volumes by Square Enix, with the first volume released on June 21, 2002 and the final volume released on December 27, 2008.

Switch was animated as 2 OVAs by ACTAS, Inc.. Square Enix released a series of 4 vocal CDs for Switch.

Plot
Two new investigators at the Narcotics Control Department in Japan, Kurabayashi Hal and Eto Kai, struggle against drug dealers, gangs, murderers, psychopaths, and mysterious organizations, in particular the notorious drug ring known as Ryuugen. But the gentle and caring one of the group, Kai, has problems of his own: he can become a cold-blooded, killing machine under certain scenarios. As the NCD works toward bringing down Ryuugen, however, answers began to arise, threatening to reveal the truth behind Kai's alter ego and exactly who the young criminal investigator is.