Nintendo He doesn’t intend to let his guard down fight against emulators and piracy. A few months after filing a lawsuit against Yuzu, the Japanese giant revealed why it likes to sue left and right. The company made it clear that They will not allow their intellectual property to be violated..
Reportedly VGKRecent statements from Nintendo’s patent attorney provide additional information about legal strategy of the company. In a presentation at Tokyo eSports Festa 2025, Koji Nishiura, Deputy Director of Intellectual Property at Nintendo, discussed the legality of emulators under Japanese law.
Nishiura clarified that emulators themselves are not illegal. However, its use may constitute copyright infringement under certain conditions. The lawyer explained that If the emulator copies the program code the original hardware or software it emulates, violates existing copyrights. This also applies if the emulator bypasses the security mechanisms implemented on the original hardware.
Emulators are not illegal, but Nintendo will not allow them.
The manager also elaborated on the concept of advanced applications, a term used in Japanese law to describe third-party tools that provide access to pirated software. Nishiura mentioned R4 case for Nintendo DS, a flash card that allows you to download games. on your Nintendo laptop without having to purchase them.
Other examples are “Freeshop” or “Tinfoil”, two applications. homemade beer which allow you to download and install 3DS or Switch games without purchasing them. These tools, according to Nintendo’s lawyer, also constitute infringement because they provide access to copyrighted material.

Nishiura stated that If the emulator prompts users to download pirated gameswill be against the law.
The legal basis for Nintendo’s actions lies primarily in Japan’s Unfair Competition Prevention Act (UCPA). This law allows Nintendo to take legal action against organizations that distribute tools or software that promote copyright infringement. Although this law only applies to the Asian country, Nintendo has no problem prosecuting alleged violators outside of Japan.
The last victims of this crusade were Yuzu and Ryujinx.two Switch emulators that went out of business in 2024. Nintendo also put pressure on Valve to prevent the release of the legendary Dolphin emulator on Steam.
Source: Hiper Textual

I am Bret Jackson, a professional journalist and author for Gadget Onus, where I specialize in writing about the gaming industry. With over 6 years of experience in my field, I have built up an extensive portfolio that ranges from reviews to interviews with top figures within the industry. My work has been featured on various news sites, providing readers with insightful analysis regarding the current state of gaming culture.