Complex sentence: The group's 12th major single, "Namida Surprise!", was released on June 24; it included a handshaking event ticket and a ballot for selecting a member that would headline its next single.
Split into simpler sentences: The group's 12th major single, "Namida Surprise!", was released on June 24. It included a handshaking event ticket and a ballot for an election that would select a member to headline its next single.