Though they have been friends for more than three years, it wasn't until a photo shoot brought them together that the idea for SHINee's Key and Infinite's Woohyun to collaborate on a musical project came to fruition.

The resulting project was the duo's new group Toheart.

"We are close so we decided to shoot a pictorial and it was there that Woohyun suggested to the CEO [of SM Entertainment, Kim Young Min] about the two of possibly releasing an album," Key recalled in an interview for this month's issue of the Korean edition of InStyle Magazine.

According to Woohyun it was the merger of Infinite's label Woolim Entertainment with SHINee's label SM that allowed the collaboration to happen.

"I thought it was a joke," he said. "But our labels had merged so we were finally able to release an album together."

In an appearance on Tuesday on the radio program "Cultwo Show," Key elaborated on the photo shoot that launched Toheart as a band.

"Since I'm good friends with Woohyun, I told him we should do a photo shoot together, saying, 'let's just do a simple photo shoot,'" he said. 

"However, people liked it and said, 'you might as well release an album together.'"

The result was Toheart's six-song debut EP, appropriately titled "The 1st Mini Album." Released on March 9, the album included a guest appearance from Jae Yoon of MC the Max.

According to Woohyun, it was appropriate the group was appearing in a fashion magazine like InStyle, since the pair seem to share a brain on the subject.

"We both share a major interest in fashion, so when we look through magazines, we send each other photos of new collections [we like]," he said.

But Woohyun admitted that similar taste does not apply to the culinary realm.

"Our tastes in food are not the same," he said. "Key is from Daegu, but he likes Italian food, and I only like native Korean food."