Is Kidou Senshi Gundam SEED C.E. 73: Stargazer hentai?
English title: Mobile Suit Gundam SEED C.E.73: Stargazer
No
Rated PG-13 (Teens 13 or older) on MyAnimeList and not tagged as Hentai.

ONA · 2006 · 3 episodes · PG-13 - Teens 13 or older
Mecha, Military, Sci-Fi, Space
In C.E. 73, tensions between Naturals and Coordinators continue to persist, eventually leading to another war between the Earth Alliance and PLANT. Sven Cal Bayan is a Natural pilot of the elite EA squad, the Phantom Pain, and carries out his squad's various anti-Coordinator missions without fail. Selene McGriff is a Coordinator researcher at the neutral Deep Space Survey and Development Organization (DSSD) and a developer of the GSX-401FW Stargazer space exploration mobile suit. Though their backgrounds are completely different, the expanding war will nevertheless force their paths to collide. (Source: ANN)
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