Kiva had a lot of plotholes in it, that's why I voted for it. I mean are the 1980's people so incompetent to leave the problem to Wataru and company... ALWAYS? And all of the Fangires just happen to lay low for a couple of years, only to rise back the same amount of years as with everybody later on? I mean when you look at the story, episode 1 1980 deals with monster A, which is later on dealt by 2000. Episode 2 1980 deals with monster B, which is later on dealt by 2000. Too freakin convenient. And where the **** does that Dragon Castle come from anyway? And it has a fucking time traveling door? C'mon, Kiva totally pushed the boundaries of imagination that it ended up being silly. A lot of wasted power-ups and equipments too since most just appeared in 1 or 2 episodes, then disappear into history. Kiva was all-over the place.
I love me some love stories too, that's why I loved Femme and Ryuki's couple moment in the movie. So no, lovestories ain't the problem with Kiva. In fact, the only thing I liked about Kiva was Otoya, and his funny-turned-tragic love story.
Decade on the other hand... Was just a waste of story, nothing makes sense... I couldn't even explain why I hate it... Considering the fact that I loved the BLACK and Amazon episode arcs so much it gave me goosebumps while watching it, so no, fanservice ain't the problem there too.