Atharva's Mupphozhudum Un Karpanai and Renigunta Johnny's 18 Vayasu have a similar story arc. Apparently both films explore the theme of obsessive love where things can go from cheery romance to dark and dreary in a heartbeat and the protagonists are believed to have certain psychological issues.
However, the makers of both films are not worried since both are supposed to be original scripts which have been handled very innovatively. Besides Atharva and Johnny are both working very hard and are trying to prove their mettle as actors. So this will just be a healthy competition.