Natsumi Hinata

Just like her brother, Fuyuki, she is a parody of herself, with her anger and just generally mean disposition exaggerated to the point of insanity. Also, she randomly has an obsession with lemons and screams the name of the fruit frequently, for no particular reason. Also, similar to... well, pretty much every incarnation, nearly everyone is attracted to her, though in this series, people stalk her, always following her to her house.

History of Characterization
Generally, Natsumi's personality wasn't altered very much from the original script. Though when Mont came along, he (as usual) made her a bit more random and scatter-brained. Specifically, in the writing for Episode 3, RabidSonicFan added a line about her threatening to stab Keroro's eyes with lemons, which devolved into a running gag/random injoke throughout the episode. RabidSonicFan then made her use it in even more episodes, causing her to have an obsession with it. Lemons also has a connection to a similar injoke, involving "Banannas" (coincidentally both of which are yellow fruits).

Relationships
Keroro - Due to Natsumi's overall hateful demeanor as well as her forcing Keroro to be a house-slave, they both have a mutual hatred of one another. By now, though,Natsumi has threatened Keroro so frequently that he grew apathetic to her constant barrage of insults. Despite this, Keroro has briefly lusted over her on occasion, usually resulting in her just being completely bewildered.

Giroro - He briefly had a crush on Natsumi, but other than that, they basically have no relationship.

Fuyuki - Being brother and sister, they have the typical sibling rivalry... though it conists of Natsumi demeaning Fuyuki in whatever way she can while Fuyuki just whimpers and takes it. When she doesn't feel like doing this though, they get along just fine otherwise.

Saburo - Though they only meet in Saburo/Kululu's debut episode, Natsumi is attracted to him (once again, like everything else), though, as-of-now, it's unknown if the feeling is mutual, seeing as he has yet to make more appearances.

Koyuki - Once more, like everything else, Natsumi and Koyuki are good friends. As usual, Koyuki has an attraction to Natsumi (though in one episode, it's briefly implied that they have a sexual relationship).