In 2016, Nintendo entered a legal dispute with MariCar, an Osaka-based company offering tourists Mario Kart-themed tours of the city using modified go-karts. The service included costumes based on the Mario Kart roster and alluded to the games' items in its advertising, jokingly asking customers not to attack each other with "banana peels" or "red turtle shells." Nintendo filed a complaint with the Japan Patent Office in September, arguing that the company's trademark was deliberately over-evocative of that for Mario Kart. Four months later, however, the office denied Nintendo's request, noting that "MariCar" was not a common abbreviation for Mario Kart, and thus the two trademarks did not conflict.

As the Japanese legal system does not include fair use protections for parodies, Nintendo subsequently sued MariCar the following month for copyright infringement due to the unauthorized inclusion of Mario character costumes. The case was ultimately decided in Nintendo's favor in September 2018, with MariCar being forced to drop the Mario Kart iconography and pay Nintendo ¥10 million (roughly equivalent to $89,000 USD) in damages. The company attempted to appeal the case to the Japanese Supreme Court, who rejected the motion in December 2020 and increased the fine to ¥50 million (approximately $483,000 USD). MariCar has since rebranded as Street Kart in the wake of the lawsuit.