Natsumi as seen in Episode 6
|First Appearance||Episode 1|
Natsumi lives with her mother Aki Hinata and her brother Fuyuki. She gets caught and tied up twice when Keroro breaks into their home, leading her to develop an adverse relationship with him and his crew. While she can usually get along with the platoon, their antics easily get on her nerves. She's usually the first to question something or to get angry over it, her temper can be very short, and she can be fairly sarcastic. By Season 3 she is so used to being annoyed by the platoon that she no longer knows what it's like to have fun.
There have been several hints throughout the series that Natsumi has a hidden interest/fetish for bondage and/or rape. By Season 2, the writers did not like this running joke and dropped it.
Natsumi is capable of being around the platoon without any problems, but they can anger her very easily; they once did so three times in two days. Episode 10 suggested that she was aware of Giroro's then-crush on her, and while she did not reciprocate his feelings, she was at least glad he had not harmed any of her other potential love interests. After Giroro stopped pursuing her and started a relationship with Dororo, the two instead became good friends.
She is the subject of a school-wide obsession: literally every girl at her school, most notably The Lesbos, is in love with her on a worrisome level. She is less-than happy about this and does not consider any of her admirers to be genuine friends. She considers Koyuki to be the only real friend she has, and she would rather that Koyuki didn't try to push their relationship further than that. The credits in Episode 18, however, show her finally willing to begin a relationship with Koyuki.
She had a crush on Saburo in Season 1 and liked to listen to his radio show to have her existence validated by a man instead of a woman. Despite this, she was guilty of not even noticing him in the very first episode, such is Saburo's lot in life.
Koyuki: "Is that the bracelet of rejection...?"
Natsumi: "Of course not. It's the Permanent Friendship-Zone Bracelet! *Suddenly serious* Let's stay friends. Just friends. You're the only real friend I have." - Episode 10