After successfully reintroducing King Ghidorah and Mothra, Tanaka and Tomiyama felt reintroducing MechaGodzilla was the next step for the series. Thanks to the success of appealing to the female audience with Mothra, Tanaka also wanted to reintroduce Minya, but director Takao Okawara had low opinions on the 60's films. So a new baby Godzilla was introduced and Rodan was chosen to be the second monster to be reintroduced instead.
Godzilla vs MechaGodzilla II was meant to be the last Godzilla film in order to avoid competition with Tri-Star's American Godzilla remake that was originally planned for a 1994 release and to honor the passing of Godzilla creator and director, Ishiro Honda.
Using the remains from Mecha-King Ghidorah, the Godzilla Defense force known as G-Force builds a new weapon to combat Godzilla in his likeness. Godzilla and Rodan must fight Godzilla's robot doppelganger if they want to bring the baby Godzilla back home.
Godzilla vs MechaGodzilla II does not have an actual good guy vs bad guy story. Mainly, both sides are neutral in this one making it hard on which side you want to root for. That is what's so good about this film. You have reasons for both sides. On Godzilla's and Rodan's side they are trying to get the baby back, but on the human side Godzilla and Rodan are posing a threat to Japan and G-Force must defend the country with MechaGodzilla even if both are just there to retrieve the baby. On the other hand, it is also a flaw because I want to be able to cheer for either one or the other knowing that there is a good guy and bad guy involved. So it's kind of conflicting. The story does not bring much to the table other than Godzilla has a child and Godzilla gets a new upgrade on his radioactive breath being more powerful than the regular. However, it does hint at his fate two movies later. The baby Godzilla looks a lot better than Minya in the aspect that it doesn't act very humanized and looks more like a dinosaur. At least he doesn't talk or look like he's Barney the dinosaur. One thing to note is that Godzilla vs MechaGodzilla II is not a sequel to Godzilla vs MechaGodzilla or Terror Of MechaGodzilla nor does it make any reference to any of those movies. The reason why it's titled the way it is I do not know. Perhaps it's to differentiate from the other films so it's not confusing, but then that makes it more confusing.
Despite the conflict of not knowing who to root for Godzilla vs MechaGodzilla II is actually pretty good. It gets a little tedious to watch, but this is at least where the story starts to pick up again.