The urge to anthropomorphise our computers and software can be irresistible, especially when systems run slow, or are difficult to manage.
The operating system on a computer, say Microsoft Windows XP or Linux, is the interface you look at every day.
On discussion boards and fan sites with bases around the world, these systems are discussed not as to how their code works, but as anthropomorphised characters, drawn in the Manga style.
The systems are said to have started as an affectionate comment about the Windows '95 operating system which was prone to stopping.
The character that emerged was a green haired girl with a habit of freezing up or stopping at odd moments. So, began the development of the OS-Tan.
OS-Tans were originally created by fans and users of computers and the idea has spread across the internet so that now there are characters for not just operating systems but also some of the programs within them.
From Firefox to Opera, Chrome and Windows 7, Ubuntu and Norton products, there's a character for most programs.
Ruth Keattch, a Manga and Anime artist based in the UK, points out: "The programs and operating systems are usually depicted as sisters and there are comic book stories online where you can follow their adventures. The Tan suffix makes a name cuter, it's like a term of affection. It's very Japanese."
With the launch of Windows 7, internet rumours were spreading that it might have an official OS-Tan.
Asako Miyata of Microsoft Japan set the record straight, "Although OS-Tan for Windows, known as Nanami Madobe, is not an official character, nor marketing initiative run by MS, we are delighted to see great enthusiasm among our user community over OS Tan and Windows products."
In Taiwan, Silverlight has its own official character. Elsa Wen of Microsoft Taiwan explains, "The idea was initiated by the Taiwan Developer Platform Evangelist team. It was created to trigger more interest for developer communities using Silverlight technology and so the character was created to attract their attention."
The way the cartoons are drawn are supposed to reflect how users feel about each system.
"Windows XP-Tan has a huge bust and is a bit slow. She was depicted as an operating system that was considered to be bloated and resource intensive," says Codie Morgan. "The Chrome-Tan wears skates which is supposed to reflect speed."
Not all OS-Tans are girls of course.
"There is a collection of male characters, they are called OS-Kuns but they don't seem to be as popular as the Tans," Nopy, a blogger and writer for the website Forever Geek, explained to the Outriders program on Radio 5Live.
The OS-Tans are more popular in Eastern countries but their following is growing.
Nopy puts this down to a need to personify the machines we may work with every day.
"I think with the original OS-Tan the artist wanted to show their frustration, but decided to make it a likeable character," he said. "I think that's a more helpful way of dealing with a system."