From what I found online, it was a Kansai tradition that was also popular in the red light district. It got commercialised so stores had something to sell during Setsubun in a similar way as Valentine's Day and White Day. Wikipedia also said that while people have heard of it, there are big differences between regions with regards to how many people actually partake.So that was a red light district tradition, make famous because a corporate chain? I thought it was actual Japan-wide tradition.