Hoshi no Koe, Top wo Nerae! Gunbuster Recommendations
Gunbuster is the original pretty girls in mecha with heart wrenching emotions anime. VoaDS updates this theme to post Eva levels of teen angst. If you've seen one, you must see the other.
Somebody called Hoshi no Koe "the serious and abridged version of Gunbuster". There is more than a little truth to this sentence. Shinkai's work was done, after all, in the true Gainax style: borrow a lot of things from everyone who did mecha anime in the past 20 years and blend them into something that nobody ever managed to create. Homages to the old Gainax OVA are completely evident (the uchuu kaiju are back, the Lysithea is a polished Exelion...) and many plot points are similar. Directorial style is much influenced by the 90's Hideaki Anno.
Similar Plots and similar Pacing of Events. Plus Both involve young girls piloting Mecha!
Both about girls separated with friends by space and time. Main characters became victims of Einstein's general theory of relativity...
Similar stories where time-space distortion draws a young military girl and her classmates far apart from one another. Both deal with the uncertainty of knowing what's become of those you're separated from, and how, though living in separate worlds and aging at different rates, in the end, you're still the person your friends always knew.
Both use relativistic time dilation as a major plot device. Also, Voices of a Distant Star uses some production techniques and elements that seem to be directly influenced by Hideaki Anno.
Gunbuster and Hoshi no Koe relates to similar plots with sci-fi elements introduced to the audience. Influential or not, both anime deals with the concept of mecha warfare in a futuristic setting.
The characters become pilots and are a driving point to the main story. In their story also brings forth distance, tragedy, and a familiar mood bought about by consequences. Some of these consequences deals with loss because of an invasive force that threatens their existence. Otherwise, both anime possesses a familiar mood that will catch your attention in its eye catching ways.