Siddhu tries to make Kumari jealous by romancing his neighbour Madhu, but his ploy fails. She rejects his marriage proposal, saying he does not have the maturity to love her. Siddhu grows suspicious about her virginity and Kumari realises this. His friends tell Siddhu is not Kumari's first boyfriend and she may have had past relationships. They fall in love Siddhu is often confused by Kumari's bold and daring attitude. Siddhu meets Kumari, a struggling model from Mumbai who has recently moved to the colony. His friends Shankar, Srinu and Suresh steal money from people who use the local ATM they hide in some local ruins for three days and Siddhu cooks for them and provides liquor, receiving a share of the money in return. Siddhu aims to be a chef on a cruise liner in Singapore and his financial status does not support him. His father Ravikanth is accused of having an extra-marital affair that leads to the separation of his parents. Siddhu is a chef leading a middle class life with his mother in K.G.B. The film was remade in Kannada with the same title in 2018.
It was declared a commercial success based on the return on distributor's investment of ₹100 million and became the 12th highest grossing Telugu film of the year.
The film grossed ₹380 million and earned a distributor share of ₹180 million during its run. It received mostly positive critics reviews praise was directed towards the film's climax, performances, cinematography and music. Kumari 21F was released worldwide on 19 November 2015 in about 500 screens. Principal photography commenced in December 2014 and was finished in 70 working days according to Rathnavelu, lighting played a key role during the filming process and digital low lighting photography techniques were used. Neither Prasad nor Rathnavelu charged any remuneration for the film. Rathnavelu was its director of photography. Devi Sri Prasad composed the film's music and R. Sukumar took inspiration from his college days in Razole where a young woman went to a picnic with some young men a major undertaking for a woman at that time, which earned her the undeserved label of a "loose" character. The film was produced on a budget of ₹60–150 million. The core plot of the movie was reported to be inspired by the 2004 French movie Lila Says. The film's centrepiece revolves around Siddhu's realisation and his attempts to unite with Kumari after an incident. Siddhu's friends doubt Kumari's character and she rejects his proposal, citing a lack of maturity. Kumari 21F focuses on a romantic relationship between Siddhu, a chef and Kumari, a struggling model. Motion Pictures, the film stars Raj Tarun and Hebah Patel. Kumari 21F is a 2015 Indian Telugu-language romantic drama film written by Sukumar and directed by Palnati Surya Pratap.