Pop star Justin Bieber took time out from his busy schedule on Saturday (22Jun13) to meet a young fan recovering from a life-saving kidney transplant.

The teen idol's reputation has taken a hit recently due to his bad boy behaviour, but he showed his kind side when he invited eight-year-old Marisa Cox to chat with him before his concert in San Diego, California.

The youngster, who was born with Down Syndrome and suffers from kidney disease, was treated to a manicure and pedicure before getting a backstage pass to meet her idol at the Valley View Casino Center.

Bieber took to his Twitter.com page after their meeting and shared a photo of Marisa kissing his cheek, writing, "One of the best parts of the job. Nice meeting you Marisa. Stay strong for me!"