It may surprise you that the concept of Otaku is not as well respected in Japan as you might think, especially in the 90s.

Hikaru is an aestavalis pilot recruited alongside Ryoko and Izumi onboard the Nadesico, she's an avid otaku of in-series anime Gekiganger, more so than Akito and Gai, doing everything from shipping characters, drawing doujinshi and building dioramas and models. She's portrayed as an extrovert which fits in well with the straight talking Ryoko and the more sarcastic dry whitted Izumi.
But like everyone on board the Nadesico, it's not so clear cut as she has a deeper back story, while spending time building models with Seiya the resident head engineer, she turns him down when the subject of relationships is brought up, an unresolved history between her and her ex-boyfriend being the cause, it's never made clear what those issues are but the lack of romantic interest in anyone implies that she was hurt emotionally and hasn't gotten over it.
It was often too easy to say that all Otaku are society's rejects back in the day, Japan is no different to the west in that regard, but Hikaru is portrayed in a way that makes her likeable and sympathetic.