PFC Garland is a soldier from Earth who was brought to Gamindustri to test out Histoire's theory of multiple dimensions and the inhabitants of said dimensions. But little did he know of the events that were following close behind upon his arrival.
You can find out more about PFC Garland and his story here: https://www.fanfiction.net/s/11624093/1/Hyperdimension-Neptunia-A-Dimensional-Trip
PFC Garland