In blistering midday heat, traffic blasts by, spitting out exhaust and grit at the busy intersection of Yotsume and Shin Ohashi Avenues. I've exited Sumiyoshi Station on the Toei Shinjuku Line, eager to find Sarue Onshi Park, said to be pretty with streams and water features. About to produce a water feature of my own (sweat, that is), I take desiccative action by ducking under the fresh white noren curtain flapping in front of soba shop Oedo.

A little zaru (bamboo strainer) of cold, hand-cut noodles and tempura seems like the perfect refresher before exploring this area of Koto Ward. My order arrives with a mystery item in the tempura, something resembling a cactus flower.

"That's a dragonfruit bud from Miyakojima," 64-year-old chef Masao Ooka calls out from the kitchen. "I scour the markets at Tsukiji every morning to find unique seasonal treats. We used to have five other soba restaurants on this stretch of road and now they're all gone; for my business to survive these days, I've got to be very serious."