Could this be the cake drawing in question? I stumbled upon this while scouring the web for AoSTH production material (because why must l̶o̶w̶l̶y̶ SatAM fans have all the fun?). According to the Tumblr post where I found this, this was used for the AoSTH episode "Sloww Going". I decided to see if any such scene where Sonic gets cake on him appears in the episode, and... Look at that. Sonic's all caked up. Personally, I don't see the "Japanese" in this concept drawing. Just looks like a slightly off-model drawing of DiC Sonic.
