Never underestimate Tokyo's capacity to throw up new and hitherto-unheard-of alchemic food combinations. Here's a future classic I came across the other day: pizza with fukinoto — wild butterbur buds, a strongly bitter and aromatic sansai (wild herb of spring) that's a bit of an acquired taste for some.
I had it in a combo pizza: half the said wild herb with parmesan; the other half shimonita-negi, a Japanese version of leeks. Washed down with Belgian white beer. Impressive and interesting, rather than essential!
Here's a close-up [apologies for less than brilliant photos]...
These are some freshly harvested fukinoto (they grow in a corner of our garden)...
And this is what they look like in the wild (photo taken from a nice post on sansai on Waka-san's excellent blog about Shinshu)...
And here are some I got from a supermarket the other day, so probably cultivated rather than foraged from the wild...