Shimeji for Mac — Does It Work? (And a Better Native Option)

Q: Does Shimeji work on Mac?

Technically yes, but with friction: Shimeji is a Java application, so it needs a JRE installed manually, and recent versions of macOS (especially on Apple Silicon) frequently cause window-layering and permissions issues that don't affect Windows. Many Mac users report it crashing, characters not appearing above other windows, or Gatekeeper blocking the unsigned jar file.

Q: Why does Shimeji keep crashing or not showing on my Mac?

The most common causes are: no JRE installed (Shimeji requires Java separately from macOS), macOS Gatekeeper blocking the unsigned .jar, and Apple Silicon Macs needing a Java build with native ARM support rather than running under Rosetta. Screen Recording and Accessibility permissions must also be granted manually for the mascot to sit above other app windows.

Q: Is there a native Shimeji-like app for Mac that doesn't need Java?

Yes. Pets Therapy is a native macOS app (Mac App Store) that gives you the same 'characters roaming your desktop' experience as Shimeji, with 75+ built-in pets and custom-pet support, but with no Java runtime, no Gatekeeper workarounds, and no manual permission wrangling beyond the normal macOS app prompts.

Q: Can I use my existing Shimeji character packs on Mac?

Not directly. Shimeji character packs are XML behavior files plus raw images, a format specific to the Java Shimeji engine. To bring a favorite character to a native app like Pets Therapy, you'd re-export its frames as a sprite sheet using the custom-pet importer.

Search "Shimeji Mac" and you'll find a lot of forum threads from people stuck halfway through a Java install, staring at a mascot that either won't launch or sits behind every window instead of on top of them. That's not user error — Shimeji genuinely wasn't designed with modern macOS in mind. This page covers both paths: getting Shimeji working if you're committed to it, and the native alternative if you're not.

Why Shimeji is awkward on Mac

It's a Java application. macOS hasn't shipped a JRE by default in years, so you need to install one yourself (Oracle JDK, Adoptium, or similar) before Shimeji's .jar will even open.
Gatekeeper blocks unsigned jars. Because Shimeji isn't notarized by Apple, macOS will often refuse to run it without you explicitly overriding Gatekeeper in System Settings.
Apple Silicon complicates things further. On M-series Macs, you need a Java build with native ARM64 support — running an Intel-only JRE under Rosetta works but adds another layer of things that can go wrong.
Window-layering permissions. For the mascot to visually sit "on top of" other windows and climb their edges, Shimeji needs Accessibility and Screen Recording permissions granted manually — an easy step to miss.
No official macOS build. Every fork (Shimeji-ee, Shimeji-Ojou, etc.) is still fundamentally the same Java engine — none of them ship a native macOS app.

How to actually get Shimeji running on Mac

If you want to try it anyway, here's the general path — expect some troubleshooting:

Install a JRE. Download and install a Java Runtime Environment with ARM64 support if you're on Apple Silicon (Eclipse Adoptium's Temurin build is a common choice).
Download a Shimeji build (commonly Shimeji-ee) and its character packs.
Override Gatekeeper for the unsigned .jar: right-click → Open, or allow it via System Settings → Privacy & Security after the first blocked attempt.
Grant Accessibility and Screen Recording permissions in System Settings → Privacy & Security so the mascot can render above other windows and detect their edges.
Launch via Terminal if double-clicking the jar does nothing — java -jar Shimeji-ee.jar will usually surface the actual error if something's still misconfigured.

If any step fails, you're debugging a Java installation, not Shimeji itself — which is exactly the friction most people are trying to avoid.

The native alternative: Pets Therapy

Pets Therapy is what you'd probably expect Shimeji to be on Mac: a proper native macOS app from the Mac App Store, sandboxed, notarized, no Java, no Gatekeeper workaround, no separate permission scavenger hunt. You get 75+ pets out of the box — cats, dinosaurs, apes, dogs, pandas, koalas, sloths, birds, fish and more — each with real walk/idle/sleep animations, and it also runs on Windows and Linux if you switch machines.

Like Shimeji, it's fully customizable: you can create or import your own pet sprites through the built-in custom-pet tools, so you don't lose the "make it your own" part of the Shimeji appeal.

👉 Download Pets Therapy on the Mac App Store · Make your own custom pet · Full Mac guide

Bringing a favorite Shimeji character over

Shimeji character packs are an XML behavior file plus a folder of raw images — that format is specific to the Java Shimeji engine and won't load in any other app, custom-pet importers included. If you had a mascot you loved, the fastest path is to re-export its walk/sit/climb frames as a sprite sheet and follow the custom pets guide — Pets Therapy's frame-per-state model maps onto the same idea as Shimeji's animation states, just in a different file format.

FAQ

Does Shimeji work on Mac?

Technically yes, but with friction: it needs a manually installed JRE, and modern macOS — especially Apple Silicon — frequently causes window-layering and permissions issues that don't come up on Windows.

Why does Shimeji keep crashing or not showing on my Mac?

Usually one of: no JRE installed, Gatekeeper blocking the unsigned .jar, an Intel-only Java build running under Rosetta on Apple Silicon, or missing Accessibility/Screen Recording permissions.

Is there a native Shimeji-like app for Mac that doesn't need Java?

Yes — Pets Therapy is a native Mac App Store app with 75+ pets and custom-pet support, no Java runtime required.

Can I use my existing Shimeji character packs on Mac?

Not directly. You'd need to re-export the artwork as a sprite sheet for a different app's custom-pet importer, since Shimeji's XML-plus-images format is specific to its own Java engine.

The short answer