Frog Fangire, also known by his human alias Takeo Ōmura, is a Fangire from the Amphibian Class and an antagonist in Kamen Rider Kiva.
Ōmura created the Black Star violin and assaulted those have respect for his creation, such as reducing his violin to a show piece or playing badly with it. When Yuri Aso played badly with his violin, the Frog Fangire attacked her but was fought off by Garulu. Ōmura later finds Otoya Kurenai playing the Black Star after he took it from Yuri and his skillful violin-playing makes the Frog Fangire see Otoya as a worthy owner of it. Though he turns being the violin's owner down, Otoya has Ōmura promise to not feed on humans again and helps him escape to start a new life by disposing of the Black Star.
Ōmura kept a music player that plays Otoya's music, which kept him calm and from attacking people so he wouldn't break his promise to Otoya. However, after hearing a rock group play their music, Ōmura is driven to assault them and soon fights Kiva.
When Keisuke Nago shows up Wataru saves Ōmura from and later learns from him what happened in the past. However, Keisuke refused to accept Ōmura's redemption and the Frog Fangire is provoked into attacking people again. Ōmura manages to return to his senses after Kiva deliberately misaimed a Darkness Moon Break and allowed the Frog Fangire to flee However, he was soon found by Keisuke, who fatally wounds him with Ixa's Ixa Judgement. When Wataru arrives, Ōmura apologizes for breaking his vow before dying from Ixa's blow, with his shattered remains reuniting with the disposed Black Star.