Bong Cheol-Hee (Lee Yi-Kyung) is single and lives on an island. He raises his nephew Bong San-Yi (Seo Woo-Jin) and niece Bong Ba-Da (Ahn Tae-Rin), who are twins, by himself. Bong Cheol-Hee is a versatile worker on the island. Even though he is a good person, with a warm heart, he can’t even think of marriage due to his situation. At that time, civil servant Jung Ha-Na (Jo Soo-Min) visits him and persuades him to participate in the Marriage Morale Boost Project. Meanwhile, Jung Ha-Na is single and chooses to stay single, but she is transferred to the Marriage Morale Boost Team due to an incident. She is given the important task of getting Bong Cheol-Hee to marry. If she succeeds in her task, she is promised a transfer to another department.