Koyomi Araragi is the main character of Bakemonogatari a story of a high school student who is attacked by a vampire and ends up meeting all sorts of mythical creatures, based on a light novel series written by Nisio Isin and illustrated by Taiwanese illustrator Vofan.
Koyomi Araragi was a normal high school student until bitten by a vampire. Although restored to humanity by Meme Oshino, some side effects of his vampirism still linger, such as night vision, superhuman strength and a powerful healing factor.
Koyomi was first conceived by Akio Watanabe for the series Bakemonogatari, but was not actually illustrated in the original light novels. His first proper appearance was in Shaft's 2009 animated adaptation of the series, reappearing in the sequel series Nisemonogatari and the prequel movie Kizumonogatari. ln all appearances he is voiced by Hiroshi Kamiya.
Koyomi Araragi is a normal third-year high school student with two sisters at home that make cameo appearances throughout the show...well, normal except for the fact that he's essentially a half vampire, and that everyone he runs into seems to be involved with an "oddity."
Oddities like a self-described tsundere girl who literally weighs 5 kg and can summon a stapler out of nowhere, a smart girl whose stress manifests itself in the form of a cat, or a lesbian with a sentient, demonic monkey arm.
Even so, Koyomi seems to feel that its his job to help these people out and free them from their oddity or at least get them under control.
Over the spring break Koyomi had a run in with a vampire and became one as well. However, a man named Meme Oshino helped him become human again
He is no longer immortal but he seems to have some vampire attributes such as extraordinary eye sight, even at night, and heals fast from wounds.
A drama CD titled Original Drama CD: Hyakumonogatari was released on August 3, 2009
Good Smile Company has made several nendoroid petit figures for the series, releasing them as separate sets. The first set containing the characters Koyomi Araragi, Hitagi Senjōgahara and Tsubasa Hanekawa.
A PlayStation Portable visual novel titled Bakemonogatari Portable that was released on August 23, 2012
A prequel to 2009 series bakemonogatari