Ahaha, already guessed he'd pick Chifuyu-nee for the winner. Is his denseness a result of being a repressed siscon or he's just naturally prone to missing the point? Of all the girls I'd say Houki, despite going first, was the least aggressive in her advances, and her intentions were probably the most pure, and that's saying something.
Cecilia and Charlotte can probably vie for the closet pervert medal.
Tatenashi doesn't count because she's being quite open in her teasing, extreme as it may be. She might be finding it her life's calling to mercilessly tease Ichika as far as she can.
They really took the entire episode for the fanservice though, and didn't move the plot one bit, if anything, except the part near the end.