It was originally the case that fresh fish was difficult to obtain in Kyoto (with the exception of freshwater fish such as carp), so it was only natural that food like sashimi, which required fresh seafood, would develop in Edo, where there was an abundant supply of fish known as 'Edomae' (the sea near Edo).
そもそも京都は、コイのような淡水魚を除けば新鮮な魚介類が得られにくいため、いわゆる江戸前の新鮮な魚介類が豊富に手に入る江戸で、刺身のような鮮度のよい魚介類を必要とする料理が発達するのは当然のことであった。