There're a few different theories as to why Kewpie tastes different than other mayonnaise brands. One theory is that Kewpie uses a different ratio of egg yolks to oil, which gives it a richer flavor. Another theory is that Kewpie uses rice vinegar instead of distilled vinegar, which also contributes to its unique flavor. Whatever the reason, there's no denying that Kewpie has a taste all its own!