How do I get a character other then the defult mascot
Viewing post in Shijima-Qt v0.1.0 is out. First beta version! comments
You can easily find many shimeji on the internet on websites like X, DeviantArt and Pixiv. You can also look them up on Google with a query like "<character name> shimeji". They're usually distributed as archives (i.e zip/rar/7z files). You can import them directly into Shijima without extracting them yourself.