Farewell to Space Battleship Yamato: Warriors of Love (1978)

Susumu Kodai and Yuki Mori's wedding plans are postponed when the Yamato crew must report to take on another threat from the stars. A new enemy has harnessed a comet and is using its terrible power to unleash destruction upon its rivals and inferiors... which are in fact everyone. The Space Battleship Yamato heads back into action. But this time, it shall not return, and much of the Yamato crew have signed on for their last voyage.