Director Karan Johar has signed Aishwarya Rai Bachchan, Ranbir Kapoor and Anushka Sharma for his next project Ae Dil Hai Mushkil. The director will work with Aishwarya for the first time. Another reason for Karan Johar's happiness is his rising popularity on Twitter, for he now has 5 million followers on the microblogging site. He thanked his followers with a tweet.