Harima, a juvenile delinquient, tries to win the love of Tenma, who has eyes only for Karasuma. This crazy love triangle, plus the large ensemble of friends and foes, and their day to day lives in High School is just the beginning of "School Rumble".
(taken from last Anime-Wiki and WikiPedia)

Picture	Name	Description
	Tsukamoto Tenma	Tenma is an undeveloped and childish girl. She is also dense, slow, unreliable and often misunderstands obvious situations. She is relatively poor student and very bad at cooking. However, she is good-natured and friendly. She loves professional wrestling and jidaigeki TV show called "The Three that were Slashed". She falls in love to Karasuma Oji. Although her classmate Kenji Harima is hopelessly in love with her, she is completely unaware of his feelings. She is also very protective of her sister, and despite the fact that she has no objection of Yakumo having a boyfriend, she is determined to protect her from anyone who tries to go further with her. For quite some time she assumed that Harima and Yakumo were dating based on the time they spent together.
	Harima Kenji / Hige	Harima is an ex-delinquent who falls for Tenma. He often struggles to confess to Tenma, though he knows she has absolutely no feelings for him and may even dislike him. He is also fan of "The Three that were Slashed", just like Tenma. He is characterized by wearing sunglasses with a mustache and goatee, this to avoid Tenma from recognizing him as the boy who saved her from a thug but was subsequently accused of being a pervert by her. He has the ability to communicate with animals, and possesses a wide variety of strange and exotic pets. This ability enabled him to communicate with Yakumo's cat Iori, which caught Yakumo's attention. He draws manga as means of escape from his problem. Whenever Harima has problems with his manga, he secretly consults Yakumo Tsukamoto, the only person he trusts with reviewing and assisting him with it.
	Tsukamoto Yakumo	She is the younger sister of Tsukamoto Tenma, distinguished by her reddish-brown, cat-like eyes and shy demeanor. Beautiful and smart, Yakumo is the most admired girl in the school, but she has never had a boyfriend. Yakumo seldom socializes with others (especially males) but easily interacts with children and animals, except for dogs. Like Harima, she is very fond of animals. She initially becomes friends with Harima because of his caring nature towards her cat. Her interest in him is further increased when she learns of his ability to communicate with animals. She has an innate extrasensory ability to literally read minds who express interest in her. The only male whose mind cannot be read is Kenji Harima, whose heart belongs to her sister. Unlike Tenma, she is well-versed in homemaking skills such as cooking and sewing. If there is a fault within her, it is her tendency to fall asleep practically anywhere, especially when in school.
	Karasuma Oji	Karasuma is Tsukamoto Tenma's love interest, often depicted as a stonefaced eccentric. As the school year goes on, the two get increasingly closer thanks to Tenma's own incredible determination to be with him. He is a largely unemotional character, reacting calmly in stressful situations. Although he is usually shown looking out the window during class, he is aware of the goings on around him. He also has a few quirky habits. Karasuma is secretly a famous mangaka, publishing his works under the pen name of Nijo jo.
	Sawachika Eri	Talented, beautiful, wealthy, and popular, she is admired and envied by her classmates for the glamourous lifestyle that many believe her to lead. However, Eri uses this image and her outward confidence to mask her inward feelings of loneliness and insecurity. She is a fast learner, picks up most skills and ideas very quickly. She is also a very versatile athlete. But she is not skilled at domestic chores such as sewing and cooking. She eventually finds herself unwillingly attracted to the school's most infamous delinquent, Kenji Harima, after his mistaken confession of love to her
	Suo Mikoto	Mikoto is a close friend of Tsukamoto Tenma. She is tall and well-developed, but is also tomboyish. Mikoto is a good athlete, she has a black belt in Kenpo and is often seen sparring with her childhood friend Haruki Hanai. Although she is always trying to help out others, she is a rather klutz when it comes to facing her own relationship emotions. She had a crush on a previous senpai two years her senior, who tutored her in middle school and helped her get into Yagami High School. However, she gave up on him after discovering that he got a girlfriend after he went to college.
	Takano Akira	She is the president of the Tea Club and a close friend of Tenma Tsukamoto, Mikoto Suo and Eri Sawachika. Akira is very perceptive, resourceful, intelligent, and also very mysterious. She has the ability to see through the true intentions of people, and her enigmatic face always hides schemes she creates to help her friends or play pranks on her classmates. She has a tendency to incite others by prompting them with information she knows will produce an explosive reaction. Despite her stoic exterior, she is loyal to her friends and goes to extremes to protect them. She is very ambitious, always putting a lot of effort into earning money. Her official job is in a bookstore, but in a side story during summer break she is seen as a bodyguard protecting a young mafia heir in Italy, and acting in a similar capacity later in Japan. She has some uncommon hobbies such as planning war games and seeming to enjoy wearing full body costumes.
	Haruhi Hanai	As class representative of 2-C, Hanai takes his duties seriously, always trying to keep his classmates (especially the males) in line. Unable to have second thoughts, he always says exactly what comes into his mind regardless of the consequences. He attends the same dojo as Mikoto and has a black belt in kenpo as well. He is one of the best athletes in Class 2-C. He is hopelessly in love with Yakumo Tsukamoto, so strongly that she can read his mind literally from a mile away. Yakumo has not explicitly rejected him, but Hanai persists even though it is obvious that she lacks interest in him.