A Japanese company, which owns the trademark for “Animoji” in the US, is suing Apple for using the word to name its iPhone X feature.

The Tokyo-based company, Emonster, filed the suit on Wednesday in US federal court, saying, “Apple made the conscious decision to try to pilfer the name for itself.” The company’s CEO, Enrique Bonansea, is a US citizen living in Japan.

Emonster owns an iOS app called Animoji that launched in 2014, which lets people send emoji that are animated in a loop like GIFs. The app asks you to compose the message kind of like how you would format a line of code in Python or Javascript, with parentheses and brackets that separate the kinds of effects you want to add to text or emoji. The app costs $0.99 on iTunes.

The iPhone X’s Animoji feature, meanwhile, lets people transform their face into customized moving emoji, taking advantage of Apple’s face recognition technology. It was the funniest and quirkiest thing about Apple’s new flagship phone. The lawsuit alleges that because both the Animoji app and the iPhone X feature are on Apple’s platforms, and because they both involve moving animation, the court should rule one out.

According to the suit, Apple knew about Emonster’s ownership of the Animoji trademark because the app is in the Apple Store. Apple allegedly offered to buy the trademark, and when it was turned down, kept using the name anyway.

Although Emonster has owned the trademark for Animoji since 2015, Apple filed a petition this September to cancel the trademark, so the registration is now under review. Apple said that because of a filing error, Emonster registered the trademark to a nonexistent business and therefore can’t actually own “animoji.”

Emonster is seeking an unnamed amount of money in damages and a court order to immediately block Apple from continuing to use the name. We’ve reached out to Apple for comment.