Yeah... maybe it's not such a secret and he just thinks the eyepatch is cool or whatever... or maybe he has two differently-coloured eyes. =P
Reinard, this is a shounen series - anything between a male and a female that involves treating the other even a little more importantly than the others (friends, etc.) means romance. xD Or at least, that's how I've come to interpret it.
But yeah, there isn't anything definite - but this is leading there.
If she's imprisoned, the logical thing to do is get out, no? ==> get power, get out of the bubble! ^_^