Subdimension

亜空間 Akuukan

Referred to by some as Hyperspace

The subdimension is a plot important place in Tokumei Sentai Go-Busters.

Place Significance

It is the place where the Transport Research Center and Messiah were sent 13 years before the start of the story. Hiromu's parents, Youko's mother, and Ryuuji's Sempai were in the Transport Research Center when this happened.

In the present day, it is the place from which the Vaglass transport their Megazords using the Metaroid as a Marker.

It is learned that Jin Masato survived the transport and is alive in the Subdimension. He sent his Buddyroid, Beet J Stag, to act as a Marker. This allows Jin to send an avatar to the real world, thus allowing him to fight as Beet Buster. J's Marker System also allows them to transport BC-04 and SJ-05 from the subdimension to this dimension.

Naming as Hyperspace

This comes from Nakamura's computer displaying that it's a Hyperspace Monitoring System. This makes sense since Nakamura was trained to monitor the subdimension.

There are times like in episode 20 which show a clear picture of one dimension labeled as Hyperspace, connected by a wormhole to another plane that's labeled as Properspace.

It really depends on if the creators of Go-Busters intend for the subdimension to be the space intersecting our dimension that's used for teleportation. If so, that would fit a commonly used sci-fi definition. Hyperspace.

However, this does not appear to be how the term is used in the series. If this were the case, then the weapons and other items teleported using the Transpod would need to travel through hyperspace to arrive at its destination in our dimension. So far in the show, we have seen no evidence of items appearing in the subdimension then reappearing in the current dimension. Megazords also seem to take some time to transport from the subdimension to this dimensioin, but that might be because of how much mass they have.