Geronimo Hongo is an alien who appears as a supporting character in the anime NieA_7. He is established as a member of an alien idol group and presents himself as a glamorous and successful figure, often attending social gatherings for aliens in the Enohana district. Geronimo frequently claims to be a high-class alien, specifically stating he is a member of the elite +5 class, the highest social rank in the alien classification system. His overall demeanor is one of pride and confidence, bolstered by his perceived status and handsome appearance.

However, his role in the story is defined by the dramatic revelation that his entire identity is a fabrication. It is eventually disclosed that Geronimo is not a +5 class elite but is, in fact, a low-class alien of the -7 rank, the very same level as the protagonist, NieA. Central to this deception is his antenna, the key physical marker of alien status, which turns out to be a fake. This discovery shatters his carefully constructed persona and leads to a swift and severe social downfall. Following the exposure of his true class, his circumstances degrade rapidly, and he is seen in humiliating situations, such as appearing in doll-like clothing and suffering a profound fall from grace.

Motivations for Geronimo likely stem from a deep-seated desire to be seen as successful and superior, driving him to live a lie. His relationship with NieA becomes pivotal, as she is instrumental in unraveling his deception. Ultimately, he becomes entangled with her and ends up in a pathetic state, discarding his food alone. His character arc is therefore one of tragic deflation, moving from a place of fabricated elite status to the reality of his low-class existence. In supplementary material like the comics, his misfortune is even more pronounced, with incidents such as a failed attempt to launch him from a human cannon, further emphasizing his role as a pitiable character. No information is available regarding specific notable abilities he possesses.