How many 'guest' characters are in Gantz
Characters that resemble characters from other series-
The captain of the karate team looked like Ryu, but got his ass beat
Countryside General also resembles Ryu, or Akira from Virtua Fighter
The Lara Croft girl, well, Lara Croft
The Sniper in the Temple mission reminded me of Golgo 13, and his name is Togo, the same as Duke Togo of Golgo 13
and this one really doesn't count, but Homo's stalker reminded me of Violet from The Incredibles.
Are there any missed?