Kenji discovers that his penis is too big to enter Milfa, due to the difference of sizes between humans and elves.
Kenji and Milfa get married, and are the only ones in the church for the wedding except for the minister, due to a high level of general tension and dislike between humans and elves.
Kenji, meanwhile, finds the lair of the Harpies: female, angel-like creatures who are known to abduct and rape young men so as to have children.
A review from Mania.com described it as "definitely a show that qualifies as a couples hentai or an easy introduction to the genre, especially for those who don't intend to go much farther but want something a little naughty".
[1] Anime News Network called it "a series that's so innocent and frilly it might not appeal to hentai watchers at all, but packs enough ass that it can't be shown to people that look down on porn".