Learning to live with a step-dad can be tough, especially if your new dad is a unicorn! Issei Uno is still in high school when his mom remarries. His mom's new husband, Masaru, is a nice enough guy, he just happens to be a unicorn. Sometimes in the form of a talking horse, sometimes in the form of a beautiful man, Masaru is determined to run the household while his wife is away and win Issei over. For better or worse, now Issei is stuck teaching this unicorn man how to be a good dad in this idiosyncratic comedy about the magical connection of family.