Earlier, B2ST's Yoseob and A Pink's Eunji released their collaboration single "Love Day" for A Cube Entertainment's seasonal project "A Cube For Season". In celebration for the release, A Cube and Mnet launched a special event named "Be My Partner".

The contest requires fans to sing a cover of Yoseob and Eunji's new collaboration song "Love Day" in either ‘B2UTY version’ or ‘Panda version’. The B2UTY version only contains Yoseob’s voice and the Panda version only has Eunji’s voice.

Fans can fill in the missing sections to create a duet with their favorite singer, and upload it on streaming sites such as Youtube and provide the link to A-Cube’s official Facebook page. Applications will be accepted for about 15 days from March 14 to 31. Yoseob and Eunji will personally judge the videos and the top 2 winners will win a dinner date with Yoseob & Eunji.

On March 14th, Yoseob tweeted, "Sing a duet of Love Day. I’ll get dinner for those who sang it well. Let’s have dinner. For real. It’ll be fun", referring to the event.