| 羽瀬川 小鳩|
|Age|| 13 (Vol 1~5)|
14 (Vol 6 onwards)
|Date of Birth||October 18|
|Job||Middle School Student|
|School||St. Chronica's Academy|
|Japanese Voice||Kana Hanazawa|
|English Voice||Alison Viktorin|
|Novel Debut||Hasegawa Family Affairs|
|Manga Debut||Chapter 6|
|Anime Debut|| Episode 1 (Cameo)|
Episode 3 (Official Debut)
Kobato Hasegawa (羽瀬川 小鳩, Hasegawa Kobato) is the female secondary tritagonist from the Boku wa Tomodachi ga Sukunai series. She is Kodaka's younger sister and is a student in the middle school division of St. Chronica's Academy, and becomes the sixth member of the Neighbors' Club, (with Yozora's approval) despite her juniority. She is very close to her brother, and behaves in a jealous and clingy way whenever she feels that he is not giving her the attention she deserves, almost to the point where it is obvious that she has a brother complex. She sees Maria as a rival for Kodaka's brotherly affections and often gets into fights with the latter.
The reason Kobato cannot make friends, (or rather, doesn't want to make any friends) is because she is under a constant self-delusion of being a Gothic vampire, and being naturally shy. In fact, she is wildly popular with the other students of her class, boys and girls alike.
Kodaka mentioned that Kobato looked more like their mother (a fact Tenma Kashiwazaki also noted), having golden-blond hair and blue eyes. Kobato mainly keeps her hair flowing down but still has two small horse tails from each side. Kobato is usually depicted in her Gothic Lolita dress, thigh-high socks with a black barrette. She also wears a red-eye contact lens on her right eye to match the anime character she's usually cos-playing.
During Summer, Kobato initially was dressed in her home clothes (From 2 years ago) which consists of a pink shirt and a skirt but later, changed to a more summer friendly version of her Gothic Lolita dress. Kobato also owned a pink bikini and it was said that she loved it very much and used to wear it every day in the past.
Kobato also almost always carries a patchwork stuffed rabbit with her (since it is the mascot of the anime character she likes).
Kobato is a shy person that doesn't tend to interact with the people around her. She is extremely close to Kodaka, and gets jealous if Kodaka diverts his attention from her.
During her 7th grade year, Kobato saw the second season of the anime "Kurogane no Necromancer" and after that has developed an obsession with it. She has had a penchant for darkness, vampires and the macabre ever since.
As a result, she often speaks in an affected fashion, claims to be known as the ancient vampire "Reisys VI Felicity Sumeragi", and wears a Gothic dress and a red contact, but this facade quickly breaks down when she gets emotionally worked up and she speaks in a strong Kyūshū accent.
Indeed, her behavior does not, for the most part, differ from that of a regular girl (procrastinating with her homework, staying inside when it is hot, etc.) which Kodaka points out, causing her to be embarrassed and slightly lose character.
Kobato has a rather serious brother complex, as she gets angry when someone else, females, Maria, in particular, gets too close to Kodaka and call him big brother, or onii-chan.
Despite having the tendency to avoid strangers, Kobato seems to appreciate people who would act like a guardian to her, particularly her brother and Yozora. However, Kobato is not particularly fond of people who act aggressively in gaining her attention, particularly persons like Sena.
- Reisys VI Felicity Sumeragi (Self-proclaimed)
- Sumeragi (By Yozora)
- Poopy vampire (By Maria)
- Kobato-chan (By Sena)
- Honorable Younger Sister (By Yukimura)
- Poopy Sushi (By Maria) 
- Dummy Vampire (By Maria) 
- Blood Sucker (By Maria) 
- Queen of the Hookers (By Maria)
- Hook Queen (By Maria)
Sadly, in terms of studies, Kobato is not the brightest of the members. She has shown that she is not very good at mathematics and took a long time to try and solve a math problem given to her by Kodaka (which she ultimately, did not solve). Kobato also displays a rather, limited vocabulary, frequently getting words wrong and not understanding other words.
Kobato is also rather naive in some sense as she would sometimes, get tricked by Maria and Yozora (although the latter was trying to trick Maria). She also tends to contradict herself, and if her mistake is pointed out to her, she would often revert back to her old personality.
However, that being said, Kobato does have excellent memory in the area of her favorite anime/manga series, Kurogane no Necromancer, being able to memorize many trivia and facts about the show and would often show anger to those who tried to pretend to be knowledgeable about the series.
- Just like her brother, Kobato's surname, Hasegawa (羽瀬川) literally means "Shallow River of Feathers".
- Kobato's given name (小鳩) means "Little Dove".
- Kobato claims to have access to the Akashic Records.
- Kobato once said that she prefers Pepsi over coca cola.
- Before becoming obsessed and influenced by her favorite anime, Kobato's old hobbies include breaking chopsticks with her buttocks; this was not mentioned in the anime adaptation.
- Kobato was voiced by Kana Hanazawa, who provided the voice of Ruri Gokou, a.k.a. Kuroneko from the Oreimo anime series. Like Kobato, Kuroneko likes cos-playing after the main character of her favorite anime series (in the same Gothic Lolita fashion), and shares the same cryptic speech pattern when talking to her friends.
- Kobato's favorite anime series, "Kurogane no Necromancer" is shortened into "KuroNec" a few times in the anime. KuroNec sounds similar to Kuroneko, however, this might have been coincidental.
- "Kurogane no Necromancer", Kobato's favorite anime series' name is an allusion to Fullmetal Alchemist (鋼の錬金術師 "Hagane no Renkinjutsushi") including a similar design on its title card.
- When in her vampire persona, Kobato would use "Ware" when referring to herself and would call Kodaka "my other half". However, when she reverts back to her normal personality, she would use "ucchi"(An Osaka dialect) to refer herself and would call Kodaka "An-chan".
- The small fights between Kobato and Maria may be an allusion to how Yozora and Sena often fight.
- Kobato's favorite foods are meat dishes and pork ramen with lots of garlic.
- In episode 2 of Boku wa Tomodachi ga Sukunai NEXT, the character in Sena's galge physically resembles Kobato.
- In the light novel, it is noted by Kodaka that Kobato had allergies as a child.
- Kobato is the sixth tallest member of the Neighbor's Club.
- In the live-action film adaptation, Kobato is portrayed by Sayu Kubota.