Setting up a desktop buddy requires a few simple prerequisites to run successfully on modern operating systems. System Prerequisites

is a fan-made interactive desktop pet that allows players to bring the beloved, kind-hearted Prince of the Dark from Deltarune right onto their computer screens. Shimejis—originally created in Japan—are tiny, animated characters that roam around your monitor, climb your browser windows, and interact with your user interface. Given the immense popularity of Toby Fox's Undertale and Deltarune series, custom creators have designed highly detailed sprite sheets to transform these interactive mascots into the fluffiest companion you can host on your PC. What is a Shimeji?

Imagine a tiny, animated version of your favorite character that can walk, climb, and play right on top of your computer screen—even over other windows. That is the magic of a Shimeji (しめじ), a Japanese desktop mascot program. These small, interactive creatures bring life to your screen by mimicking user behaviors, interacting with icons, and performing a variety of adorable actions that can help relieve stress and add a spark of fun to your day. Think of it as the 21st-century version of those classic desktop pets, but cuter, more customizable, and powered by the open-source Java platform.

Whether you seek a quiet companion to meditate at the edge of your monitor or a mischievous little guy to climb your windows, the "shimeji ralsei" is a wonderful, delightful, and heartwarming addition to your PC. The only question left is: are you ready to let the fluffy boy in?

They will scale up the sides of your monitor, dangle from the top ceiling of your screen, or sit peacefully atop your open windows.

This version often feels slightly more "playful" because you can clearly see his expressions. Without the shadow of the hood, his big round glasses and small blush are more visible. He scampers and frolics with the same boundless energy but feels a bit more personal. If you are a fan of Ralsei's true design, this is the version to get.

: He will walk along your taskbar or crawl up the left and right borders of your monitor.

A Shimeji Ralsei is not perfect. Here are some honest cons:

In a fan-imagined story, a user downloads a "Shimeji Ralsei" only to find he’s much more polite than the average desktop pet. While other Shimejis might toss your browser windows around, Ralsei spends his time "healing" your broken shortcuts and offering invisible cups of tea near your cursor.

If you need to concentrate or if he is blocking your view, you can send him away temporarily.