They have another thing in common. Both are Bollywood's children.
Karan's father Yash Johar worked as a production controller for B R and Yash Chopra, Dev Anand's Navketan banner and Sunil Dutt's Ajanta Arts before becoming one of India's nicest and successful producers.
Sharmishtha's dad Sudhendhu Roy began his career as Bimal Roy's art director. He worked with the maestro until Bimalda's death in 1966, went solo and became one of Bollywood's most respected art directors. He also directed five films including the critically acclaimed Uphaar (1971), starring the then Jaya Bhaduri, and Saudagar (1973) with the unusual lead pair of Amitabh Bachchan and Nutan.
Art direction was a natural move for Sharmishtha.
Interestingly, her mother wanted her to do a course in interior decorating, much against Sharmishtha's wish. "My mother believed I should do a professional course, which I did. Later, I assisted my father for six years. I started out by drafting for him, which meant that I would sit across the table and he would tell me draw this line perpendicular to this, draw a line there etc," she said.
Image: Amitabh Bachchan in a scene from Kabhi Alvida Naa Kehna. The background is ample foil for Bachchan's outlandish character in the movie.
Also read: KANK, the story in pictures