We made another name to represent that we'll continue to work as a team in the future and put out good music."

Entertainment released a teaser announcing Toheart, a special unit duo consisting of Woohyun of Infinite and Key of Shinee.

[7] On the same day, the duo held their first showcase in the Coex Artium, hosted by bandmates Minho and Sungkyu.

[10] Both Woohyun and Key stated that it was their idea to create this unit, since both are friends and they had interest in working with each other.

[2][11] On April 7, 2014, the duo followed up their promotions with "Tell Me Why" featuring Infinite Sungyeol’s little brother, Lee Dae-yeol as well as actress Mun Ka-young.