I play a lot of KIA as White, and never as Black...Dunno why...

But that 8.h3 deserves a "??". The real power of the KIA, the way I saw and play it, was that as White, you have to be decisive, fast, and single-minded. That move deserves a ?? - it's too cramped on the kingside to launch a "Fischer attack"?  or basically using the g pawn as a battering ram, plus the Q+B battery ends ANY hope of that; from that, I would say, from experience, that any decent player playing against KIA with the above position will win due to White's space. h3 is only played when starting a kingside pawn storm, or after Bg4, which uncramps my position after Bxf3 Bxf3 and removes the question of where the hell to put that knight on.

Overall, good play, good play.

This is the mate that I missed:

You've managed to get the first (and possibly most difficult to spot during the game due to the temptation of the Queen) right.

my guess at 6 you missed? other moves by white =  mate in less than 6 ...i think

Excellent play, your system of choice against the KIA demonstrates excellent knowledge of current theory.  b6 is a common idea although thanks to white's deviation, not 'book' ... Your choice to play in the center as opposed to the queenside was excellent.  White's play ... iffy :).  Great game, I personally have had troubles against the KIA in the past, a few nice concepts demonstrated here.

The more obvious and natural 9...Re8 brings no immediate advantage for Black, whereas 9...b6! is more difficult to spot but clearly much better. The normal system for Queen's Pawn games with Black playing e6 is to bring out the c8 Bishop out on the c8-h3 diagonal after the exchange of e-pawns. The a6 square is not the Bishop's usual posting, and so 9...b6 is the first step to Black's plan of putting pressure on the d3 pawn (which proved to be successful).

Why does 9...b6! deserve an exclamation point?

I agree that 5...e5 is more ambitious, but I personally prefer the flexibility of e6 - it's all a matter of playing style.

I don't usually comment on many games through sheer apathy, but this is an excellent game that I really enjoyed, with good annotation - thanks for the post

5...e6 is not at all bad, however 5...e5 is a better test of White's courage, I think.