Who/What is Domo-kun?
Domo-kun is a small brown open-mouthed monster hatched from an egg
who lives with a wise old rabbit underground. He really, really
likes TV and also enjoys rocking out to Guitar Wolf. Domo-kun is
the mascot of NHK's BS2 (a satellite channel; he also appears on
BS1). NHK has been producing a series of Domo-kun stop-motion
vignettes that exude personal charm and warmth. There is also a
wide variety of Domo-kun-related merchandise available, some of
which is difficult/impossible to find in the US.
"Domo" in this case appears to mean more of something (usually to
stress "thank you," "excuse me," etc), implying increased
politeness. "kun" is used as "Mr." or "Ms." for "younger people or
colleagues". He acquired his name in the second episode, when
Usajii turns on the TV for him and an announcer says "Domo
konnichiwa" ("very much hello").
