For those like me who was confused about the sprite sex, I was just recently told by the game developer that the female is actually a transsexual. So your choices are really a boy or a trap. Which is fine by me, there's games with traps in them but not so many with you playing a trap.
Actually, the fact that he/she would tell me directly kinda took me by surprise.
Oh, and I was told that he/she does have plans to put the game on English DLsite for those looking to buy it but can't use the Japanese site.