Or, more logically, Otoya didn't know he had a son when he died. Wataru's mom told him about Otoya, which is why Wataru had such an image of his father. If Wataru had grown up knowing his dad, I think he'd have a lot less respect for him
Otoya knows about Kivat the second though, at least, because he guesses Kivat the third in the future era when possessing Wataru.
Plus Megumi saying "this Kiva is different" after the discussion of how Kiva is an enemy of humanity/tried to destroy humanity in the past, the Kivat descendants are different because of Otaya?
Megumi know the stories about kiva and knows that kiva has saved her, kengo, and even NAGO ( or as i like to say nasho n-ass-ho). the storys of the old kiva and the actions of wataru don't match up for i think she will go and and try to broker a deal with what she belives is the new kiva.
I honestly think that this thread should be taken more seriously. The complex 2-storyline show of Kamen Rider Kiva somehow compelled the Red Infinity Ranger from Eltar (a Red Zordon?) to make a thread which is as exciting as the Duke's rumor threads.
It has been said that Wataru's mother is a Fangire because his father Otoya fell for such a strong beauty. I think that the Queen Fangire may be Wataru's mother. She's the only female Fangire so far and she symbolizes the most powerful chess piece in the Checkmate Four, the Queen. It's very probable that Otoya will fall after her. After all, he has quite a good and high taste for women. His dancing skills probably made the Queen Fangire fell for him.