I bet the author for the original manga of "Shirokuma Cafe" (しろくまカフェ), Aloha Higa (ヒガアロハ), must have giggled her lungs up when she came up with this animal-based aidoru group by the name of Yama Arashi that exists in the comfy world of sentient animals and humans. Yamaarashi（山荒）just happens to mean porcupines and guess who's arguably been the top aidoru group on the Johnny's Entertainment heap for the past several years?
Panda-kun's mother and her buddies from the neighborhood are just bonkers over these cute and spiky wonders while the main characters are somewhat bemused to say the least.
In any case, their Yama Arashi's theme song did come up in one of the later episodes of the anime "Shirokuma Cafe" called "Yama Arashi Tonight" (Porcupines Tonight!), and by golly, doesn't it sound just like an Arashi（嵐）tune? It was never used as one of the many ending themes for the show but writer and composer Saki（紗希）, who came up with all those show-enders can pretty much do it all when it comes to transcending the J-Pop genres, as she has by coming up with this oh-so-boy-aidoru tune.