Riki Naoe is the main protagonist of Little Busters! He is the character you play as in the original visual novel. This carries over into the anime as the show is told from his perspective. The show establishes this by giving him numerous inner monologues. His reaction to an event is always documented to the audience. He is a skilled artist and spends most of his free time drawing. His prowess is shown in one episode where he illustrates a picture book for Komari after she damages the one she had as a child.
When Riki was still a child, he lost his parents. The show never explains how they died in full detail, but we're led to believe it was some sort of tragic accident. This led Riki into a downward spiral of depression. Shortly after the death of his parents, he met the other members of The Little Busters! His friendship with them made him feel less alone. Their childhood adventures ultimately brought him out of his depressive state and made him feel happiness again. This is why Riki feels so attached to The Little Busters! and will do anything to keep their friendship intact.
Riki also suffers from narcolepsy. He will uncontrollably fall asleep at inconvenient times. Sometimes his narcolepsy is triggered by an overwhelming situation and other times it just happens randomly. His narcolepsy can even cause him to fall asleep standing up! The other members of The Little Busters! are all understanding of his situation and help him when he gets a narcoleptic attack. Riki's narcolepsy was a direct psychological response to the death of his parents. It started acting up right after they died while he was still suffering from depression.
Although Kyousuke is the oldest and the one who came up with the idea to start a baseball team, Riki is the real leader of The Little Busters! He never sees himself this way because he lacks physical strength, but the evidence is pretty clear. He is the one who goes out and recruits new members for the team. He is also the most sensitive and caring amongst their circle. He is the first to help out if someone else has a problem they are facing. In fact, most of the show's story lines revolve around another member of the team facing some difficulty, which Riki then helps them overcome. Towards the end of the series, Kyousuke officially bestows the title of leader upon Riki.
Kyousuke is the oldest member of The Little Busters!, being one year older than everybody else. He is in his third year of high school, which means he will graduate at the end of the year. He realizes that when he graduates, their circle of friendship will no longer be as close as it once was. Because of this, he decides The Little Busters! should do something eventful to commemorate their last year together. Kyousuke comes up with the idea of starting a baseball team, which everybody likes.
Kyousuke is one of the most popular boys in the school. His good looks make it so all the ladies pine over him. He is often ambushed by random female students he has never met before who try and flirt with him. Many of the male students also look up to Kyousuke as a role model. However, Kyousuke remains humble about all of this. He never talks down to people or comes across as better than anyone.
Kyousuke is also the owner of a Steller's sea eagle named Chirpy. When Kyousuke was younger he took a trip to Hokkaido. He met Chirpy there and the bird would not leave his side upon his return. He trained and raised Chirpy before realizing the bird was unsuitable to be a pet. He had to begrudgingly send Chirpy back to Hokkaido. However, in one episode Chirpy comes to the school and the two reunite.
Rin is Kyousuke's younger sister. She is the opposite of her brother in many ways. Kyousuke is popular and outgoing, however Rin is alienated and shy. Her shyness overwhelms her and is a byproduct of her social anxiety. Her social ineptness prohibits her from engaging with new people or expanding upon her circle of friends. Her only friends are the other four members of The Little Busters! This means that all her friends are male and she has no friends of the same sex.
However, this changes throughout the series. As Riki recruits new female members to the team, Rin slowly begins to develop friendships with them. She becomes especially close with Komari. In the early stages of their friendship, Komari bandaged one of Rin's cats when it was injured. To repay her, Rin gave candy to Riki to in turn give to Komari. This situation is evidence that Rin will always maintain her shy personality, but has the potential to make new friends.
As hinted at by the above situation, Rin is also a loving cat owner! She has five cats who she cares for dearly. Some of her cats are named after famous pop culture figures like (John) Lennon, Audrey (Hepburn), and (Osamu) Tezuka. Rin is protective of her cats and they are protective of her as well. At one point, she gets into a fight with Masato and her cats stand in front of her as a barrier. To protect Rin, they then proceed to attack Masato!
On the field, Rin is the pitcher for The Little Busters! She is extremely skilled, sometimes throwing pitches that go 130 mph! She invents several new pitches while on the mound including the meowve and the slimeow. If she sees her cats in danger, if will provoke her to throw more powerful pitches.
Every cast of characters needs a meat head and The Little Busters! have Masato. Masato is obsessed with muscles. He is Riki's roommate and it seems every time Riki opens their door, Masato is doing a bench press or lifting dumbbells. He carries his dumbbells around with him at all times. He has even been known to lift weights while sleeping! He is always flexing and showing off his biceps to others. He feels the need to constantly talk about his muscles as an attempt to bring attention to them. Scenes where he does this are played for laughs, as Masato is primarily used by the show for comic relief.
Despite his impressive physique, Masato isn't as strong as he thinks he is. He always picks fights with other members of the team when a conflict occurs. The problem is, he then loses virtually every fight he's in!
One stereotype in anime and other media is that most jock athletic types are rather dimwitted and bad at academics. This is certainly true of Masato. He does poorly on tests and always forgets his homework. This causes him to make up stories to the teacher about why he doesn't have it completed. One of his most brilliant ideas was saying that aliens came to Earth and took his homework from him!
Kengo is a skilled kendo artist who seems to have dedicated his life to its practice. He is always wearing his kendo uniform and can't seem to have a conversation without bringing it up. He also has a rivalry with Masato. The two always get into arguments that, more often than not, lead to physical altercations.
Despite being a member of The Little Busters!, Kengo doesn't show any interest in actually playing baseball with the team. He is still a part of their friend group and will attend team meetings, but doesn't actually join in when the team takes the field. This is because he usually has a kendo tournament or training session he needs to participate in.
However, towards the end of the series Kengo injures his arm and is unable to use it. He picks up a bat to prove to himself that he can still be strong with just one arm. After two unsuccessful swings, he hits a home run off one of Rin's pitches. This is the first time we see Kengo play ball with the rest of the team.
Komari is the most athletically incompetent member of The Little Busters! Riki recruits her to join the team and she accepts with great enthusiasm. The Little Busters! decide to give her a test to measure her skills. She fails every one and displays no skill in baseball whatsoever. However, Kyousuke is enamored by her passion and lets her join the team anyway.
Komari's brother died when they were both still children. She was unable to handle his death and tried to convince herself it never happened by erasing her memory. She did this successfully and forgot the whole experience. At night, her brother would still appear to her in dreams. This confused her because she forgot that she ever had a brother in the first place. However, seeing images of death cause her memory to come back and send her into despair until she can psychologically trick herself again. In one episode of the series, Komari sees a dead cat and has a mental breakdown. Riki then helps her by making her confront and accept the fact that her brother died all those years ago.
Komari has a "happiness spiral theory." This means that as long as others are happy, she is happy too. She will often go out of her way to help other people. She does this not only because she is caring and kind, but because seeing them happy makes her happy in return. This is part of the reason she develops such a strong friendship with Rin. They have a cyclical relationship as the two of them make each other happy.
Komari also has a strong sweet tooth and is often seen indulging herself with candy and pastries. She claims they are a delicacy of life and make her happy. Her habit can occasionally be detrimental to the rest of the team though. At one point in the series, Komari agrees to help Kud study, as she is falling behind in her classes. As preparation for their study session, Komari has Kud eat a bag of sweets. Not thinking about the repercussions, their sugar high makes them hyper and unable to study!
Kud is the only member of The Little Busters! who is not native to Japan. She traveled extensively as a child and lived in Finland for a long time with her grandfather. She has dual citizenship between Japan and the Island Nation of Tebua. Kud doesn't have any friends because she was never in one place long enough to develop friendships as a kid. She also has a problem with nervousness that makes meeting new people difficult for her. The Little Busters! are the first real friends she makes and joining the team is the first time she feels like she is a part of something.
Kud's mother is an astronaut on Tebua. As a child, Kud was sent to school to learn to become an astronaut. Because of her mom's status, Tebua's federal government paid for her attendance. However, Kud was a poor student. People made fun of her and told her that she waste a waste of the federal funds. Kud felt like a disappointment to her mother and the experience provoked her to run away to Japan.
The reason Kud was a poor student is because she can only grasp big concepts, not little ones. She reads dense books on physics and cosmology and is knowledgeable about those concepts. However, when an exam is actually put in front of her, she gets overwhelmed with nervousness and makes dumb mistakes like putting all of her answers in the wrong margin.
Much like Rin and Kyousuke, Kud is also a proud pet owner. She has two dogs named Belka and Strelka. Their names are references to the first two dogs the Soviets sent to space. Strelka is a Siberian husky and Belka is a Schipperke.
Despite not being born in Japan, Kud is more knowledgeable about Japanese culture than most of the other students in the school. Her room is decorated with sophisticated classics of Japanese art and she can cook Japanese cuisine better than anyone else on the team.
Saigusa is a troublemaker. She is always breaking rules and causing ruckus in the school. She gets scheduled for detention because she is late to class. This punishment doesn't seem to work though, as she just skips her detention sessions! Sometimes she uses practicing with the Busters as an excuse. She is the favorite victim of the student council's president, Futaki. Despite Saigusa's antics, Futaki seems to be exceptionally hard on her. This is because the two of them are sisters and have a troubled past.
Saigusa and Futaki's family upheld an outdated marriage tradition that had been passed down for generations. The tradition is that every wife has two husbands. As might seem obvious, this led to severe dysfunction. The second husband of Saigusa and Futaki's mother went crazy and attempted murder. He was thrown in jail immediately afterward. However, Saigusa and Futaki were each born from a different father. Only the parents know which is the daughter of the criminal and neither want to tell.
Thus, Saigusa and Futaki were constantly compared growing up. Futaki was the better student and more adept at sports. Everyone held Futaki in higher esteem than Saigusa and gave her more attention. This led Saigusa to have feelings of inferiority and inadequacy. It also led to everyone thinking that Saigusa was the daughter of the criminal. Saigusa developed a low self-opinion and a hatred for her sister. The reason Saigusa breaks the rules is because she knows it will anger her Futaki.
Saigusa is also a member of the maintenance committee. She is very skilled at carpentry and working with her hands. These skills are put to use by fixing broken desks and chairs throughout the school. She will sometimes use her duties in the maintenance committee to anger her sister as well. In one episode, she fixes a bench that is closed off because it is going to be removed from the school. Much to Saigusa's delight, this upsets Futaki because no one was supposed to touch the bench prior to its removal.
Kurugaya is the most intelligent member of The Little Busters! She is much smarter and more mature than her age lets on. She is a straight-A student who gets higher scores than anyone in the school. She is considered a genius and everyone asks her for help with their school assignments. She rarely says yes, however. This is because Kurugaya is aware of her level of intelligence. She is confident in herself and considers herself to be smarter than her peers. This makes it hard for her to relate to people, so she usually just shrugs them off.
Despite this, she is fascinated by Riki. Kurugaya has an obsession with things she finds "cute." Riki falls into this category because of his girlish appearance and because of this fixation, Kurugaya agrees to join The Little Busters!, as out of her personality as it might seem.
Kurugaya is also a trickster who loves manipulating people. When she is first introduced in the show, she plays mind games with Riki in an attempt to pick his brain. She is able to mess with people because she is so smart and her victims don't realize what she is doing.
Nishizono is the most quiet and introverted character in the series. She is always sitting under the same tree in the school's courtyard reading a book. She goes unnoticed by most of the other students. When attention is drawn to her, they refer to her as "shadowless." Riki decides to reach out to her and recruit her for The Little Busters! because she reminds him of his younger self, when he was still suffering from depression. She is reluctant at first, but eventually agrees to Riki's offer.
After joining the team, a problem arises when she tells them she has to be fully clothed and holding her parasol at all times. Nishizono is allergic to the sun and has to constantly be in shadow to avoid getting sick. This means that she can't actually participate in the game of baseball with the rest of the team. However, Riki comes up with the perfect solution to keep her on the team; he decides to make her the manager. Nishizono and the rest of the Busters all agree to this and applaud Riki for his idea.
As evidenced by the fact that she is always reading in the courtyard, Nishizono is a total bookworm. She spends nearly all of her free time reading. She tells Riki at one point that her goal is to read every book in the world. She also tells him she loves reading because it provides her with a sense of escapism. She can live vicariously through the characters she's reading about, an experience she cherishes and can't get enough of.