Series Synopsis
While walking to class, Koyomi Araragi (voiced by Hiroshi Kamiya) is taken by surprise when he sees fellow classmate, Hitagi Senjogahara (voiced by Chiwa Saito), falling from the top of the stairs. Without thinking, he catches Hitagi, discovering her secret; she is virtually weightless.
Attempting to keep Koyomi quiet, Hitagi threatens him to stay away from her. Surprisingly undeterred, Koyomi says that he knows a way to cure her condition and offers to help.
Koyomi recognizes that Hitagi has come into contact with a powerful supernatural being known as an oddity. He knows this because until recently, he was one of these mysterious creatures; a vampire to be exact.
After helping Hitagi, they form a strong relationship; first as friends, then eventually becoming a couple. They soon begin to meet several other girls who have come into contact with some kind of oddity.