On June 23, 2013, he participated in the Chinese team for a football match at the 2013 Asian Dream Cup in Shanghai. In January 2014, he participated in the "Idol Star Athletics Championship". On April 23, 2014, he was cast in the cast of "20 Once Again", directed by East Chen. A representative from SM told Newsen: "Luhan was confirmed in 20 Once Again. At the moment we're adjusting the shooting times". The film is a Chinese version of the Korean film, "Miss Granny", in which an old lady returns to be young, and premiered in January of 2015. On August 13, 2014, a post by Luhan on his official Weibo account reached over 13 million comments, thus entering the "Guinness World Records" as the person who has the most comments in a Weibo post. On August 19, S.M. Entertainment posted a photo of Luhan with his "Guinness World Records" certificate and a world record holder medal. On October 10 of the same year, he filed a lawsuit against S.M. Entertainment to cancel its exclusivity agreement, mainly due to health problems. Still in October, he starred in the remake of the music video for "The Last Game" made for "". On December 1, he released the song "Our Tomorrow" for the soundtrack of "20 Once Again". The song peaked number one position on Baidu Music Chart.