Complex sentence: The song is being used as a tie-in for TBS dorama Gomen, Aishiteru, her first single used in a drama of a commercial TV station since Eternally-Drama Mix-in 2008.
Split into simpler sentences: The song is being used as a tie-in for TBS dorama Gomen, Aishiteru. It's her first single used in a drama of a commercial TV station since Eternally-Drama Mix-in 2008.