chiyu
A Virtual Net Idol, the first of her genre of fictional characters having their own websites (alongside the parallel phenomena of Jikon websites). Opened on the 14th of February, 2001, the perpetually 12 year old VNI would become a hit as the year went on.
Beyond her website, Chiyu would partner up with several entities, and contribute to magazines as well, including the Japanese magazine Netrunner, which would not only create a figure of her, but also have her star in the OVA Netrunmon (voiced by Momoi Haruko).
Following the rise of virtual YouTubers, Chiyu was credited as one of the Pioneers in the field, alongside others such as Ami Yamato (debut 2011), Weatheroid Airi (debut 2012), Sayo-chan (debut 2013), and Infinite Loop's ILtan (あいえるたん).
Chiyu herself would end up debuting as a VTuber on the 14th of February, 2018.