Natto? ...

... we think this was natto, a fermented soy bean, and quite the Japanese acquired taste. It's not so much the flavour that is troubling, but the texture - the beans stick together, and when you pull them apart, a sticky residue stretches and dangles between, like moldy mucus. Very visually unappealing, and the sticky, slimy texture immediately sets off an alarm in your head "Warning! Warning! Botulism and horrific stomach cramps are imminent!"