Originally Posted by
JALPak
And it also could take days for symptoms to appear which means it could be caused by food you ate few days ago.
While that it certainly true, the last meal we had had where these three also ate the identical food, beyond the ramen, would have been several days before at a kaiseki the first night we arrived. Again, possible, but very, very unlikely due to the elapsed time in total, the accuracy of the problem hitting each person four days later, and just the unlikeliness that this restaurant (Kikunoi) would have been that lax.