On early maps of Edo, as Tokyo was known prior to 1868, Okachimachi is rendered as a town (machi) densely packed with the tiny dwellings of okachi — low-ranked, poorly paid samurai infantry.
Today, as I exit the Hibiya Line subway station at Naka-Okachimachi in Taito Ward and head south alongside the elevated Japan Rail (JR) tracks, I find Okachimachi still houses cut-rate valuables — indeed, it's practically pave with discount diamond outlets. The hoard of shops offering pearls, rubies and reputedly the city's best deals on ingots is broken, incongruously enough, only by wafts of fish coming from Yoshiike, a spacious seafood market that dates from the 1920s.
Continuing in a southward direction, I find a jewelry store divergent from the others. Inside Miyabica, owner and artist Natsuko Minegishi, 36, hands me one of the necklace pendants she makes on the premises. I can't determine what the light, soft, striated material is.