A Monochroid (モノクロイド Monokuroido) is a type of virtual android in the Len'en Project that usually appear on JynX's Youtube channel, helping with explanations on videos related to Len'en.
While the origins of the monochroids remain unclear, it is possible that they were an abandoned project from Tsubakura Enraku's laboratory that had been brought back into use, either as-is or after modification. Hoojiro Shitodo faintly remembers seeing similar technology and the name Rei from the lab, although she could not give outright confirmation due to not having worked on the project herself. In addition, she recalls that the technology behind the project had been frozen and even its data should have died out, leading to further confusion about its existence now.
Monochroids tend to have a long, code-like full name but are usually referred to by a shorter nickname instead.
Full names follow the following pattern:
||[character the monochroid is based on]
Nicknames are based on the number zero from various languages:
- Rei: Japanese "零" (れい Rei)
- Zelo: English "Zero"
- Lin: Chinese "零" (Trad: Líng Cantonese: ling4)
- NiLU: Similar to English "nil"
Characters that are this species
- Rei (Monochroid[Rei] = _Type_iX01[Tsubakura];)
- Zelo (Monochroid[Zelo] = _Type_iX02[Yabusame];)
- Lin (Monochroid[Lin] = _Type_iX00[Rei];)
- NiLU (type currently unknown) - their name follows the same pattern as the other three and, similarly to them, they have pale white skin. In addition, the 6th anniversary illustration shows the 3 monochroids excited at NiLU appearing in the anniversary video, akin to "a relative being on TV". NiLU was confirmed to be a Monochroid in the 7th series anniversary video.