I don't think this is a game cel. I have plenty 
of those, and these character designs don't 
match the game. They are wearing uniforms from 
early in the TV series, for one, and Ichino's 
hair color matches the TV designs (brown) rather 
than the game designs (very dark brown, almost 
black). This cel is somehow related to the TV 
series, but I just don't know in what way...