Vijay has always had a sweet equation with the child actors who have acted in his films. Here's an interesting similarity which we had found recently.
Any child artist who acts in Vijay's film first, later on, acts with the same actor after few years as his sister. The list is as follows:
Saranya Mohan - Kaadhalukku Mariyadhai (child artist), Velayudham (sister)
Nancy Jennifer - Nerrukku Ner (child artist), Ghilli (sister)
Nivetha Thomas - Kuruvi (child artist), Jilla (sister)
Apart from this, the girl who played Vijay's sister in Kaththi had already acted as a child artist in Friends. Find it interesting?