In that spirit, I decided to set natto against Marmite...
If you're interested in how to prepare natto, there are some pictures of the process below the cut:
inside each carton is a sachet of sauce, and another of karashi (Japanese mustard), with the fermented soy beans themselves underneath:
Next, stir it all with chopsticks until it becomes sticky and hazardous to passing flies:
I have to tell you that both were delicious in their way, but that Marmite won, by dint of being so... Marmitey. That said, I've now reached the stage where my hypnogogic phantasies are usually conducted in (very bad) Japanese, so it may be that by this time next year the answer will be different.