5 Takeaways From the 'Dirty Grandpa' Trailer

— -- The first trailer was just released for "Dirty Grandpa," the raunchy comedy starring Robert De Niro and Zac Efron. The film tells the story of a mischievous Dick Kelly (De Niro), who convinces his grandson Jason (Efron) to take him on a road trip to Florida for spring break.

Here are five takeaways that we gathered from the "Dirty Grandpa" trailer.

1. De Niro is playing a completely different character than any of his former roles.De Niro's character Dick Kelly is, as the title suggests, very "dirty." Kelly is a foul-mouthed army general whose idea of a good time is partying in Daytona Beach, Fla., just days after his wife's funeral.

2. Efron is playing a straight-laced and obedient kid. In contrast to De Niro's Kelly, Efron's character Jason Kelly is as straight-laced as they come, and is shocked at his grandfather's raunchy antics. The trailer shows Jason eventually letting loose and attending a spring break party.

3. De Niro's love interest is Aubrey Plaza.Plaza plays Lenore, a college-aged student on spring break who takes a keen interest in De Niro. Plaza's character invites Dick and Jason to "tag-along" to Daytona Beach with her and her friends for spring break.

4. Julianne Hough is Efron's on-screen lover.Hough plays Meredith Goldstein, Jason's fiancé in the film. While in Florida, Dick tries to convince Jason that Meredith is "not right" for him.

5. You will see Zac Efron shirtless at least once. Jason flexes his biceps on stage in Daytona, and the crowd loves it.

“Dirty Grandpa” will be released in theaters on Jan. 22, 2016.