guy on the far left got leerons vest the fat brown girl looks like minnie mouse right by harukas side is naota with the cat ta-kun behind the fat girl is yoko(only seen in one frame in the animation, but you can see her long hair here) and behind her is Nono from Diebuster in her waitress outfit
and the guy n the red jacket looks a bit like fry(futurama)
The "last you checked" must have been the first eight episodes, because it's kind of hard to be a main character when the whole story doesn't revolve around you.
AttenboroughViralNonoKaminaNiaPowerpuff GirlLeeronSimonHarukoTakkunTycho ScienceNaotaYokoMinnie MouseFryNarutoKamonLal'c Mellk Mal