This story would revolve around the Yamato's sister ship "Musashi".
the Year is 2199, and the Earth was spared a Radioactive Holocaust at the hands of the Gamalons. The Gift of Starsha has cleansed the Earth of fallout, but there was still lingering effects. Many people found themselves incapable of having children. Concern rose as the Human race feared their line dying out. So the "Eden" Project was created. Its goal, To artificially create life. These would be children free of diseases, and completely healthy. At first the Project was looked upon as a God send. the Human race cheered its endeavor. However, the fickleness of man would rear its ugly head as People were able to procreate again. This sparked many "Anti-Eden" Movements. Calling it an insult to God. So the Government scrapped the project, and demanded that the 8 examples of the project, Four Boys, and four Girls, be destroyed. The scientist couldn't bring about killing the children they worked so hard to create. they put the Children into suspended animation, and jettisoned them out into space.
The year is now 2250, and the Yamato's Sister Ship, Musashi is out on patrol. The Musashi comes across a derelict ship, and inspects the contents. Finding 8 Suspended animation capsules. Due to an unknown event all but one of the capsules have lost power, and their occupants have expired. Though the last one was still alive. The Name on the documentation was simply No. IV. the contents of the Capsule revealed to be a young girl no older than 10.
I am looking to develop this idea.
Space Battleship Musashi: