Justin Bieber's fans are working to give back the same way the pop star readily does. Several of Bieber's biggest fan groups, as well as the nonprofit Together We Rise and Brush Buddies (the makers behind the singing Bieber toothbrush), have all teamed up to work on a charity single.

"They're all working on pieces of the video and the lyrics. Right now, they're putting together videos and thank-you's.' We're working on the back end," Danny Mendoza, President/CEO of Together We Rise, which focuses on helping foster children in the U.S, told MTV News about the project.

"It started with a young lady named Vivian, she runs the Justin Crew fan club and she approached it on Twitter. She approached it and she had a lot of fan support," he continued. "She took it upon herself to take a leadership role, and then she contacted me because she needed some guidance. We just decided we'll help you do it. Justin Bieber had tweeted about us in the past and helped us get some recognition, so it was a thank-you to him as well.

Proceeds from the song will go toward Bieber's Believe charity drive. It will drop in March, just in time for his 18th birthday on March 1.

"I'm almost 100 percent positive that they know," Mendoza said of Bieber's camp's knowledge of the project. "Justin Bieber inspired a lot of young people to give back. It's a thank-you for helping us and we want to give back in your honor."

Bieber is certainly not a newbie to the world of charity. Mendoza said that having a pop star like Bieber being so socially conscious has been incredible for the charities he helps bring attention to.

"He definitely has the right people around him ... They made it a priority that giving back is more. I think his relationship with [his manager Scooter Braun's brother] Adam Braun and his charity [Pencils of Promise], he was able to see hands on a lot of it."

After Bieber tweeted this week about the Trillium Gift of Life Network, the Ontario-based organ donation network has seen registrations skyrocket to more than 1,200 people, four times the amount the network usually receives.

What charity do you want Bieber to promote? Leave your comment below.