Just northeast of Palaceside Building in Takebashi, Tokyo, the Kanda-Nishikicho area was called Gojimachi-hara in the Edo period — a wide open field kept as a firebreak — and I believe I have mentioned the two vendettas that took place there. Entering Meiji, Tokyo University Preparatory School, Kaisei School (present University of Tokyo), Gakushuin, Tokyo Law School (present Hosei University), Anglo (British) Law School (present Chuo University), and others were established, forming a major cultural and educational district fragrant with learning. The Gakushikai-kan=photo=, Kinjo Gakuin High School, and Seiso Gakuin High School today are traces of that legacy.
The name Nishikicho is said to come from samurai residences lining this district and two houses of the hatamoto Ichikawa family — "nishiki" (two colors) — which became Nishikicho. Another theory holds that a Bentendo enshrining insects as beautiful as brocade stood at Gojimachi-in, or that residents named it after Kyoto's Nishikikoji.
Kanda-Nishikicho was officially born as a place name in Meiji 5 (1872), but in Meiji 44 (1911) it became simply Nishikicho. In Showa 22 (1947), when Kojimachi and Kanda wards merged into Chiyoda Ward, old Kanda place names retained "Kanda," yielding Kanda-Nishikicho.
Place names ending in Nishiki appear in cities nationwide. Whether after Kyoto's Nishikikoji or from a wish for streets as beautiful as brocade is unclear, but I count at least 51 municipalities reading "Nishikicho" and 43 reading "Nishikimachi." Hokkaido alone — Kushiro, Otaru, Kitami, Abashiri, Rumoi, Tomakomai, Date, Furano, Biei, Kamifurano, and others — has 23 municipalities with Nishiki in the name, both readings combined. In Hokkaido, "Nishikicho" alone is not enough; you must specify clearly, as in XX City Nishikicho, or you may end up somewhere unexpected — take care. Kanda-Nishikicho, however, exists only in Tokyo.