Kirito's POV
Prologue
A huge castle made of stone and steel floating in an endless sky.
That was all this world was.
It took a vagarious group of craftsmen one month to survey the place;
the diameter of the base floor was about 10 kilometers — large
enough to fit the entirety of Setagaya-ku within. Above, there were
100 floors stacking straight upwards; its sheer size was unbelievable.
It was impossible to even guess how much data it consisted of.
Inside, there were a couple of large cities along with countless small
scale towns and villages, forests and plains, and even lakes. Only one
stairway linked each floor to another, and the stairways existed in
dungeons where large numbers of monsters roamed; so discovering
and getting through was no easy matter. However, once someone
made a breakthrough and arrived at a city of the upper floor, the
«Teleport Gates» there and of every cities in the lower floors would
be connected making it possible for anyone to move freely through
these levels.
With these conditions, the huge castle had been steadily conquered for
two years. The current front line is the 74th floor.
The name of the castle was «Aincrad», a world of battles with swords
that continued floating and had engulfed approximately six thousand
people. Otherwise known as...
«Sword Art Online»
