The film stars Dulquer Salmaan and Aditi Rao Hydari as a married couple, Kajal Aggarwal as a relationship counselor and Nakshatra Nagesh as a radio jockey.

In Kochi, Yaazhan, a software engineer, and Mouna, a paleotempestologist, fall head over heels in love with each other after meeting for the first time in a cafe and get married.

Mouna learns about Yaazhan's conversation and realises how much she had hurt Malar, and apologises to her for involving her in the scheme and causing her heartbreak.

In January 2020, it was reported that Jio Studios had signed dance choreographer Brinda to make her directorial debut through a romantic comedy film featuring Dulquer Salmaan, Aditi Rao Hydari and Kajal Aggarwal in the lead roles.

[4][5] Titled Hey Sinamika, as inspired from a song from Mani Ratnam's O Kadhal Kanmani (2015), the film was launched at an event in Chennai during mid-March 2020.

[6][7] The shoot commenced in Chennai after the launch ceremony, with filmmakers K. Bhagyaraj and Mani Ratnam being guest directors for the first shot.

[14] The film was originally planned to release on 12 February 2021 as Valentine's Day special, but was postponed due to ongoing COVID-19 Pandemic in India.

M Suganth, critic from Times of India gave 3 out of 5 stars and noted that "Hey Sinamika works better as a comedy than as a drama".

[20] The Hindu critic gave a mixed review, saying, "Dulquer Salmaan and Aditi Rao Hydari salvage this messy love triangle".

"[23] Sudhir Srinivasan from Cinema Express gave 3 out of 5 stars and said, "Invested performances lift this interesting, but flawed romance".

[24] Hindustan Times critic noted, "Hey Sinamika needed to be a breezy romantic comedy but what it ends up becoming is a problematic love triangle.