Throughout his life, Yukinari has been subject to torment and mistreatment from girls due to his small stature. As he enters high school, a peculiar ailment afflicts him - he develops hives whenever females come near or make physical contact. To his astonishment, Yukinari finds himself whisked away to Seiren, an enchanted realm hovering undetected above Earth. Here, he's surrounded by countless women and only a handful of men, but he's grateful to have made a friend in Miharu-chan, who inexplicably doesn't cause him any adverse reactions.