- Voiced by:
Japanese - Takanori Hoshino (Jūmonji Kazuki), Masami Iwasaki (Kuroki Kōji), Takeshi Maeda (Toganō Shōzō)
English - Kirk Thornton (Jūmonji Kazuki), Lex Lang (Kuroki Kōji), Liam O'Brien (Toganō Shōzō)
Sena Kobayakawa has been their gopher since kindergarten and at their first day at Deimon High, they order him to buy items for them. In the anime, they had only met him in class that morning. After Sena made a final dash and jumped into the MRT carriage, Yoichi Hiruma, who spotted Sena's talent for running and dodging, beat up the brothers and took pictures of them naked. Hiruma keeps the negatives of the photos and extorts them into playing and later joining the team by threatening to reveal the photos to everyone. During the Zokugaku Chameleons exhibition match, they were searching for the negatives of the pictures when Kurita stumbled upon them. Kurita wrongly assumed they were intending to join the club as linemen. Later, because of the appearance of Kurita's apprentice, Komusubi (and his constantly looking down upon the brothers), they competed with him at the Tokyo Tower and managed to pass Hiruma's qualification test (fittingly called the Tower of Hell). The three decided to quit the team later and forget about the negatives of their pictures, regardless of what Hiruma did. However, after being beaten up by Banba of the Taiyo Sphinx, they changed their minds and set out to become great linemen. Kuroki and Togano were considered as trash by the editor of a sports magazine after their match against Taiyo Sphinx, but later proved themselves as linesmen during the games against NASA Aliens. During the game against the Americans, they also learned a new maneuver called the Sweep. It was here that Jumonji shows his respect for Eyeshield by promising to open a line for him to get through. During the Death March, they learn the proper method of pushing off with their entire body, rather than just their arms. In the anime, even Otawara of the White Knights found it difficult to hold them back.The Ha-Ha Brothers have a running rivalry with Komusubi, who always shows them up in tests of strength and determination. Hiruma approves of this war of the linemen, which drives the Ha-Ha Brothers to become better players. During the Death March training in America, two of the Hah Brothers, Kuroki and Togano were about to abandon the team due to the harsh training and lack of determination, but they changed their minds once they learned that Hiruma and Kurita will no longer be able to play after their second fall season. This would be their final chance. Jumonji also pointed out that they earned more respect as linemen rather than as useless punks. It is also fair to note that their background as punks has come in rather handy in several games, where they've relied more on their streetfighting skills than actual lineman skills, like against Zokugaku and Seibu.
In the game versus Bando, when they are introduced individually, Machine Gun Sanada describes Juumonji as having the best technique, Kuroki the best speed, and Togano the most power. This is another sign of their branching out as individuals.
List of The Ha-Ha Brothersmanga. He seems to be the quietest of the three. Likes Jump, but puts it aside for a while when going to the United States, saying "Sigh, I guess American comics are alright." Compared to the others, Togano is fairly laid-back, preferring to read his manga, often just going along with what Juumonji and Kuroki want.
- In each of the boy's names are the kanji for one (Kazuki), two (Kuroki), and three (Togano). Their first names imply the number of sons born in the family. This means that Jumonji is the only child, Kuroki is the second son, and Togano is the youngest son of three.
- Early in the manga, Hiruma refers to them as the Ha-Ha Brothers seemingly because he believes (or wants them to think he believes so, just to aggravate them) that they are actual brothers
- At first, when they entered the team for the first time (due to the blackmailing by Hiruma), they only being given single locker in the team restroom for all of them. However, as they grow stronger and more determined, they finally had more lockers, one locker for every single one of them.
- In the manga, all three of them drink and smoke. After the Taiyo Sphinx game, Jumonji quit smoking when he read the 'Football Monthly' article, to focus on his game. Musashi persuaded Kuroki and Togano to quit as well (noting that "Real athletes don't smoke. Smokers lose their breath too quickly.") by swearing off smoking himself. Whether they still drink or not is unknown.
- Though it is not certain why Juumonji is actually very popular with girls, mentioned constantly by Kuroki and Togano ("Dammit! Even though we were never confessed too..." [Kuroki] "Though I wonder how many times it happened to Juumonji." [Togano] "Ah?" [Juumonji]).
- In the anime, Kuroki and Togano actually do abandon the team during the Death March unconvinced by Doburoku's reasonings. Jumonji runs after them, stunned when Kuroki revealed his knowledge of the negative article against him and Togano, furthering his reasons for leaving. Jumonji punches the two, saying that they can change their reputation like Sena did. After a long fistfight, they agree to return together not for the team's sake but to prove their self-worth to others.
- Another shtick they do is finish each other's lines or thoughts one by one based on age. The order would then be Togano (the youngest), Jumonji (the middle), and Kuroki (the oldest). (i.e.: Togano: "So that would mean..."; Jumonji: "what we have to do is..."; Kuroki: "Yeah. We have to believe in our teammates' strengths more."). It should be noted that when this occurs, Kuroki often has the longest quote of the three. In the manga, they say one thought in unison.
- Jumonji and Togano have unique nicknames used only by the trio: "Kazu" and "Toga".
- Kuroki's seiyuu also voices Cerberus and Togano's seiyuu also voices Unsui.
- All three have taken to Hiruma's habit of kicking a teammate in the rear, (for them it's simultaneous), without saying anything, whenever that teammate does something spectacular.
- In the recent manga, the Ha?! shtick trio has been added into the fourth one by their lineman party Komusubi, ending with "Han!" (Ex. Togano: HA?! Jumonji: HAA?!! Kuroki: HAAA?!!! Komusubi: HAN!).
Techniques and Strategies
- Screen Pass - They intentionally let their opponents break through the line, then shift over to make two-on-one blocks on the other side of the line of scrimmage. This creates a wide area for Eyeshield to go through once Hiruma laterals the ball to him.
- Delinquent Death Blow - Also known as the Juvenile Delinquent Murder Method, the Scumbag Scuffle, and Rascal Killing. The Hah Brothers practiced the technique with the Zokugaku Chameleons.
- Sweeper - A method in which linemen form a protective barrier in front of Eyeshield, thereby clearing a path for him in a diagonal direction. After the Death March, they are able to clear a very wide passage for him to go through.
- Hip Explosion - During the Death March, the Ha-Ha Brothers learned the proper method of pushing out with their entire bodies, rather than just their arms. By thrusting out their hips, they can deliver more force against opposing linemen. Kuroki in particular exercises this move against the seemingly unbeatable Aoyanagi in the game against Amino.
- Ha Ha Triple Attack - Shown in the anime first, a three-on-one tackle with each Ha Ha brother using their own strengths as a means of gradually nullifying quick and sturdy opponents. Kuroki leads, first using his speed to cancel the runner's sprint. Togano then uses his power to beat the force of the runner's counter. While the opponent is distracted, Juumonji uses his techniques (often being the Juvenile Delinquent Murder Method) to finish the move. Alternate versions include tackling from three different directions at once or tossing their opponents into the air. Recently, in the manga, this was shown when they saved the ball from Teikoku's possession after failed Chris Cross. In here, Kuroki and Toganou hold Reisuke Aki from holding/ securing the ball, while Juumonji batted the ball down. Jumonji's father seems to hold a different opinion of the gang as he watches the technique.