This reminds me of Vandread, really. A guy who is special in a women dominant environment.
Ichika isn't spineless and isn't a pushover also. He's an average guy, not shy(Rito Yuuki in earlier chapters) or nosebleeder(Ikuto) or dumb(Keitaro) or perverted(Tomoki). What I like here is the Battle of the Sexes. Not typical in today's anime.
As for the Harem candidates, I like Houki's Tsundereness, especially the scenes in the rooftop and the room sharing.
And Cecilia from Britannia looked like the daughter of CC(Hey it's Yukana!
) and Lelouch. (All HAIL Britannia)