What is a "Sendaikko"? From "Chiyo" to "Sendai," city of trees

Sendai, the City of Trees. Its name is said to begin when Date Masamune rewrote the old "Chiyo" as "Sendai."
"Sendaikko" is a word for someone born and raised in Sendai.
The key is how the name "Sendai" came to be — from the old "Chiyo" to the green city's byname.
What "Sendaikko" means
Sendaikko means someone born and raised in Sendai, spoken of with the castle town Date Masamune founded and the city's green streets.
Sendaikkosendaikko
It means someone born and raised in Sendai, often spoken of with the castle town Date Masamune founded and the city's green streets.
From "Chiyo" to "Sendai"
The place was once called 'Chiyo'; around the time he built Sendai Castle, Masamune is said to have rewritten it, with the same reading, as 'Sendai.'
Chiyo
The place was once called "Chiyo" (千代). Around the time he built Sendai Castle, Date Masamune is said to have rewritten it, with the same reading, as "Sendai" (仙台) — some link the characters to a Chinese poem about a terrace of immortals.
City of Trees
Sendai is called the 'City of Trees' for the greenery of the Hirose River, Mount Aoba, and its tree-lined streets and garden groves.
Mori-no-Miyako
Beyond the Hirose River and Mount Aoba, Sendai's streets are rich with roadside trees and garden groves, earning the byname "City of Trees." The name mirrors the city's scenery.
Written forms (仙台 / 仙臺)
The reading is 'sendai,' with 仙臺 as the older written form — the sound of 'Chiyo' was kept while only the characters changed.
仙台 / 仙臺
The reading is "sendai"; the older form is written 仙臺. The reading of "Chiyo" was kept while only the characters changed.
FAQ
Do people call themselves "Sendaikko"?
Yes. With pride in growing up in the City of Trees, people of Sendai call themselves Sendaikko.
Who founded the city of Sendai?
Date Masamune. He built Sendai Castle and laid out its castle town, shaping the city.