According to the police complaint lodged by the victim yesterday, she was sexually assaulted by Santosh Pawar (23) on Valentines Day, which also happened to be her birthday.
The girl used to attend coaching classes at Khadegolavali in Kalyan where the accused befriended her, APSI V K Hirey of Kolshewadi Police Station said.
After her birthday celebrations, the girl was allegedly raped by Santosh on the terrace of the coaching class building.
Based on the complaint, police have registered an offence under section 376 of the IPC and Protection of Children from Sexual Offences Act of 2012.