Singer Navi sang an OST for KBS2TV's Three Brothers! The song is called Cannot Reject, and is the title-song of the drama. The song was released on October 29 through music portal sites. A representative of Three Brothers stated, "Navi has outstanding skills and an attractive voice that matches well with the drama, so we requested for her to sing the OST." This will be her first OST song ever since her debut. Navi commented, "I am happy and honored to take part in the OST of a drama that is receiving a lot of love." If you don't know who Navi is, (shame on you) she is known for her songs Heart Damage and Wasteful Tears. Navi - Cannot Reject Cr: urnobody919 Navi - Heart Damage Cr: Mardi09 Navi - Wasteful Tears Cr: Mardi09