Cibo Matto like writing songs about food. I could fill up many more volumes of ASAF focusing squarely on the howls and beats laid down by Yuka Honda and Miho Hatori. However 'Birthday Cake' is probably the angriest, and really that's what's important. Granted they're not angry at the birthday cake, but then it's hard to be mad at birthday cake.
The song is probably about a mother making a cake for her son on his thirtieth. It's also a violent recipe. But it's mainly about Shutting Up and Learning To Eat.
