H. Kawai states that this film is not a serious political social drama. It is a romantic comedy, or 'human drama', which depicts a man who is thrown into various situations when his wife unexpectedly becomes Prime Minister. The film focuses on the spouses' attempts to reconnect with each other.
"The First Gentleman" tells the story of ornithologist Hiyori (Kei Tanaka) and his wife, Rinko (Miki Nakatani), leader of a small political party. One morning, she asks Hiyori if he would mind if she became Prime Minister. Hiyori asks her to repeat the question, but Rinko says nothing, so the man, still confused, sets off to a remote island to birdwatch.
While he spends his time on the expedition with no access to the outside world, Rinko is elected the first woman Prime Minister and Hiyori, unbeknownst to him, becomes the first First Gentleman in Japanese history. Hiyori had always supported his wife's career ambitions, but he had no idea what life had in store for him.