---
title: "Patents, Copyright, and Legal Protection of IP in Japan"
url: https://memocore.ai/memos/6a5f62e363d783ad68709399
project: "Doing Business in Japan"
tags: "japan-business, intellectual-property, unverified-opinion"
updated_at: "2026-07-21T12:15:31.247Z"
---

# Patents, Copyright, and Legal Protection of IP in Japan

Chat participants say Japan lacks classic patent trolling — mass registration of unrelated trademarks for later shakedowns — though individual large companies do aggressively defend their own brands: Nintendo's well-known attempt to shut down a 90-year-old pizzeria called "Mario" over the Super Mario Bros trademark did not succeed. Unlike in the US, patenting common game mechanics does happen and gets approved in Japan despite the questionable value of such patents, comparable to Microsoft's early-2000s patent on the mouse cursor. As an illustrative case of patent trolling outside Japan, a formula for optimizing the Abs (absolute value) function in the OCaml compiler turned out to be patented by Oracle; OCaml's developers abandoned the optimization because they lacked funds for a legal defense (patent: https://patents.justia.com/patent/6073150). Chat participants rate copyright and patent protection in game development and software in Japan as underdeveloped — "medieval," in their words, an unverified opinion — and describe B2B/technical patent disputes in Japan as effectively "won by whoever has the more expensive lawyers." A separate legal precedent involved a lawsuit against Sony over whether an internet service provider infringes copyright by giving access to subscribers who pirate content; Sony lost the case. At some Japanese universities (for example Keio), a procedure exists to prevent theft of technology, particularly technology related to weapons of mass destruction, governed by the Foreign Exchange and Foreign Trade Act (FEFTA); an example document is at https://www.st.keio.ac.jp/en/admissions/docs/08._Pledge.pdf. Specialized insurance is available in Japan for developers and technical staff, covering accidental copyright infringement or damage from critical code bugs, though no specific products were detailed in the chat.

Source: https://patents.justia.com/patent/6073150 — Oracle's patent on the Abs function optimization, cited as an example of patent trolling in software development. Source: https://www.st.keio.ac.jp/en/admissions/docs/08._Pledge.pdf — Example of Keio University's non-disclosure pledge for technology under FEFTA requirements.