OH MY GIRL BANHANA is a sub-unit of the popular South Korean girl group OH MY GIRL, debuting on April 2, 2018, in South Korea and later in Japan on August 29, 2018. Made up of three of OH MY GIRL's members—Hyo Jung, Binnie, and Arin—the group was managed by WM Entertainment in South Korea and Sony Music Japan in Japan. OH MY GIRL BANHANA announced their debut in 2018, followed by a series of teasers. The group intrigued fans with promotional photos set in a jungle surrounded by bananas and monkey costumes, hinting at their debut mini-album's theme. BANHANA, OH MY GIRL BANHANA's first mini-album was released on April 2nd, with "Banana Allergy Monkey" as its lead promotional single. The song achieved a high level of popularity and the group quickly became a favorite among the existing OH MY GIRL fanbase, developing a strong following of their own. The mini-album also featured the participation of other members of OH MY GIRL. Later in 2018, the group released a version of this mini-album tailored for the Japanese market, titled Banana Ga Tabe Renai Saru. During this time, the group also contributed the original song "Sweet Heart" to the drama Clean with Passion for Now. In 2020, the group released the single "뽀마이걸 반하나 for Christmas." In 2022, OH MY GIRL BANHANA released the single "Love Is."