I think the shougi thing is quite interesting, here's some posts from mangahelpers:
andin the final frame, it shows the Challenger's King.
And also the peice that Shikamaru moves is the knight...
Shikamaru shows frustration for not being able to reach the king in time
Wee.the knight (which Asuma called Shikamaru) was facing the bishop and rook, which are, as I know has been said already, what Kakuzu and Hidan's names mean. But it doesn't make sense that Shikamaru would pull Ino and Chouji along for the revenge ride. You could argue that's what the pawn pieces stood for in that same chessboard picture, but I seriously doubt he sees them as pawns.