Set in Kadamakkudy, the film revolves around Lallu, a privileged daily wage painter and his colorful gang of friends. Although he comes from an aristocratic family and is the son of Kombanaayil John, a respected criminal lawyer in the area, he prefers the company of his under-privileged friends Panchikuttan, Vicky Paedika, and Teny Sebastian. Lallu, although uneducated, has a lot of charm. Though he is adamant that he will marry for love, and is looking to find a 'spark' in a girl, and hence has not found any girl to settle down with though Jesna is attracted to him and wishes that he marries her. However, his younger brother, a well-to-do computer engineer, wants to marry his girlfriend, whose parents insist that Lallu be married first. After trying and failing to find a girl that has the 'spark' he is looking for, Lallu sees a picture of a young woman, Diya, in the newspaper, who has gone missing, and suddenly feels the 'spark'. He and his friends try to find Diya, learning about her kind nature in the process, yet cannot find her. Lallu pieces together clues he gets from the accident Diya was involved in, and in the meantime comes to know that she is dead. He figures out that she was deliberately murdered by Davis, an intoxicated youth who has psychological problems from his childhood that he takes out on anyone who mentions his mother. After getting his revenge, Lallu, with the help of his father, makes them stand before the legal system, ensuring Diya gets justice in the end. The film ends by showing that although Lallu believes he has never met Diya, he actually has on several occasions. When a small girl asks his full name, Lallu reveals that his name is Mohanlal John Kombanaayil.
Deepa Soman of The Times of India rated the movie 3 out of 5 stating: "The premise in itself might not be new, but the makers have managed to keep it quite entertaining." Deepa also praised Dulquer Salmaan's performance and wrote that it "is an out-and-out DQ show." Sify rated it 3 out of 5 stars and gave the verdict: "A suave Dulquer Salmaan saves the film." The reviewer concluded that "Oru Yamandan Premakadha is one of those films which is meant to be enjoyed without thinking too much." Cris of The News Minute gave the film a 2 out of 5 rating and wrote: "Dulquer's mass entertainer has a poor storyline." Navamy Sudhish of The Hindu said that it was "a bland treat with feel-good factors." Anna M. M. Vetticad of Firstpost rated the movie 1.5 out of 5 and concluded: "DQ looks good in lungis and is charming of course, but even his charm cannot hold up nearly three hours of exhausting wanderings." Manoj Kumar R. of The Indian Express rated it 1.5 out of 5 stars and said that "Dulquer Salmaan cannot charm his way out of this mess."
