Berry Good debuted on May 21, 2014, with the music video for “Love Letter”, a remake of the song released by Click-B in 2000. The eponymous single was released the following day, when they also started promotions on M! Countdown.
In January 2015, Asia Bridge Entertainment stated that Subin, Iera and Nayeon had left the group to concentrate on their studies, and introduced new member Seoyul, followed by Daye and Sehyung.
Their second single Because of You was released on February 9. They started promotions on February 10 on SBS MTV’s The Show. In June, their representative office launched various Berry Good goods (such as accessories, clothes and cosmetics) in China.
On September 23, their third single My First Love was released. Two music videos were produced, one of which features actress Kim Bo-ra. The song, posthumous work of composer Joo Tae-young, was first performed in advance on September 20 at Hallyu Dream Concert, and promotions started on September 22 on The Show.