[Guyver Spawn]

Quote:

Originally Posted by Switchblade

All of the Showa series explicitly took place in the same universe.

Kuuga and Agito seem to take place in the same universe. It also possible that Kuuga and Agito also exist in the same universe as the Showa riders going by the Agito PS2 game since the game's timeline has 1971 - Agito in the same timeline together. I think continuity for Rider shows goes like this:

Showa: 1971 - Black RX
Kuuga/Agito: 1971 - Agito
Shin, ZO, J and Ryuki - Decade: All stand alone. They all take place in their own continuity.
W - Drive: 1971-Black RX, Kuuga, Kiva and W - Drive.

I think W - Drive to exist in the same universe since some of the crossover movies where reference in the show. Kuuga was shown in Fourze and Kiva's belt was reference in Gaim. I do wish Toei would build their universe better similar how Marvel studios does.