Mighty Mouth delivered a reinterpretation of Turbo's "Love Is... (3+3=0)" on KBS 2TV's "Immortal Songs." Minyoung from BBGIRLS joined the stage, adding synergy, and the original artist Kim Jong-kook appeared as a surprise guest to offer support.

Mighty Mouth (Chuplex, Shorry) appeared on the second part of the "Immortal Songs" composer Yoon Il-sang special, performing their first duo stage. They expressed their determination by saying, "Our goal is high, absolutely number one," as they took the stage. Shorry had previously participated as a special guest in Ailee's stage during the Park Jin-young special in 2012.

Regarding their choice of "Love Is... (3+3=0)," Mighty Mouth and Minyoung explained, "This song is the best fit for us and Minyoung to harmonize." On stage, Kim Jong-kook appeared via screen video to conduct a 5-second countdown, and the performance prepared by Mighty Mouth and Minyoung raised the atmosphere. Kim Jong-kook also visited the rehearsal site beforehand to cheer for Mighty Mouth.

Chuplex drew laughter and cheers from the audience with a dance break using the rainbow technique, and Minyoung added excitement to the stage with her refreshing vocals. Mighty Mouth's energetic rap, stage manners, and the duo's chemistry received enthusiastic responses from the audience.

Yoon Il-sang praised the stage, saying, "If a team like this is formed, I will write songs for them," and shared his impression, "I almost got up because of the excitement." The participants also responded with comments such as "Their energy is truly the best" and "An exciting yet fully packed stage."

Last month, Mighty Mouth released a remake track "Lalala (Feat. Minyoung (BBGIRLS))" together with Minyoung.