Godai, Shouichi, Shinji, Kenzaki, Hibiki, Tendou and Ryotaro were never shipped with anyone.
I always got the feeling that Sakurako was Godai's girlfriend and they just never spelled it out. Tendou clearly had romantic tension with... what's her name, Hiyori? Boring artist chick. It never goes anywhere or gets spelled out, but that's true of so much in Kabuto.
Ryotaro I got the feeling was supposed to share romantic tension with Hanako-- to play off the gender role inversion of a super-strong woman and a super-weak man-- but the actress's departure from the series seems to have killed that.
Anyway, some female Rider leads have had things to do without the romance angle being pushed (like Sakurako). I just don't see how Hina in particular is in a position to be interesting or important without being a romantic lead. Her only other hook is "Ankh is using my brother's half-dead body!" and there's not a whole lot they can do with that for now.