This is a story about a father and a son, centered around a violin. The enemy this time is Fungaia, a vampire that feeds on life energy. The person who fights him is Red Du, who makes violins in the workshop inherited from his father. Although he transforms into Kamen Rider Kiba with the power of the belt, it is still unknown why he can transform and why he has to fight. However, in fact, Du is not the only one fighting Fungaia. 22 years ago, Du's father, Otoya, has been fighting rampant Fungaia since then. The story develops while closely linking the present where Du is and 22 years ago, before the young Otoya got married and gave birth to a child named Du. 22 years ago, the Fungaia that Otoya failed to eradicate continued to multiply and appeared in modern Japan. Du transformed into Kamen Rider Kiba and defeated him, connecting the past and the present in this form. However, there are more forms than what can be seen with the eyes. What form will the fate of people living in each era be connected to? Why does the appearance of Fungaia threaten the existence of mankind? What is the fate of Watari and Otoya who are in it? Various characters live in various times, and the story is developing. There are only two people who know about these two times... That is Shima, who organized Fungaia Hunter, and Mr. Kido who started the coffee shop "Coffee Mall Damour" 22 years ago. The key to the fate of people who rise and fall in the two times is these two people, and the violin left by his father...! ?