Vassilis Vassilikos's 1967 novel Z (made into a movie of the same name), premiered at the 2012 Toronto Film Festival. Koechlin found the role of a political activist, which she described as vulnerable and awkward to be challenging. She said that the character was, "someone who is not an accepted person [...] an outsider". Shanghai received positive reviews from critics, and was a sleeper hit at the box-office grossing over worldwide. Koechlin garnered mixed response for her performance in the film. While Russell Edwards noted the "biting edge" she brought to the role, Aniruddha Guha thought of her as the "weakest link" in the film. Koechlin's continued association with commercial films sustained her success as seen, in varying degrees, with both of her 2013 releases, the supernatural thriller Ek Thi Daayan and the romantic comedy-drama Yeh Jawaani Hai Deewani. The former was based on Mobius Trips, a short story written by Mukul Sharma, the father of Konkona Sen Sharma, who also starred in the film. Koechlin's role was that of Lisa Dutt, a Canada-based music teacher who is suspected of practising witchcraft. For her role in the film, Koechlin learned to play the guitar, and lip synced "Yaaram", one of the film's track. On its release, the film received mixed to positive reviews from critics and had a decent run at box-office, grossing over . Praising Koechlin in her review for the film, critic Anupama Chopra remarked that she was, "an interesting actor but the film doesn't know what to do with her". Yeh Jawaani Hai Deewani, which also starred Deepika Padukone, Ranbir Kapoor and Aditya Roy Kapur, was her second film appearance of 2013. She played the role of tomboy, Aditi Mehra. Koechlin, who was nursing her hospitalised mother and simultaneously filming for the project called it a "really tough time". Nonetheless, she described her time on the film sets as "fun", and developed a close friendship with Padukone. The film emerged as one of the highest-grossing Bollywood films with earnings of . Koechlin was lauded for her performance and comic timing, with News18s Rajeev Masand writing, "Koechlin invests heart and spunkiness to the part". She earned her third Filmfare Best Supporting Actress nomination for her performance in the film. Later in 2013, Koechlin appeared in a video entitled It's Your Fault, along with VJ Juhi Pandey. Dealing with the issue of sexual assaults on women, the video mocks