L.A. Boomboom (Ｌ.Ａ. ブンブーン Eru Ē Bunbūn) is a minor antagonist featured in the seventh part of the JoJo's Bizarre Adventure series, Steel Ball Run, introduced in the "The Desert Born Outlaws" story arc.
L.A. is the youngest member of the Boomboom Family along with his father Benjamin and his older brother Andre. Participating in the Steel Ball Run, he attacks Johnny Joestar and Gyro Zeppeli to eliminate competitors.
L.A. is a young man with long flowing hair, and shadowed eyes. He wears the same dotted suit as his family with a target imprinted on the chest and wears goggles on his head.
L.A. is shown to have low academic skills, for instance being unable to do basic math. Along with being prone to uncontrollable emotional outbursts, he is also extremely naive, believing that his mother was a stork because Andre told him so.
He is generally emotionally dependant on his father and brother. Likewise, he looks up to his brother like a young child would. Despite the constant verbal abuse from both, L.A. doesn't mind their insults, and is attached to them, becoming furious when his father dies.
Compared to the other members of his family, he seems to be of lower intelligence, but has sudden moments of keen observation which are only met with his family's scorn. For this, Benjamin calls him 'the family's smartass'.
- Main article: Tomb of the Boom 3
The Boomboom family's Stand, Tomb of the Boom 3, grants every member with the ability to manipulate iron in different ways. In L.A.'s case, it allows him to manipulate iron sand to immobilize his victims. He is capable of killing a person by extracting iron-rich blood from someone and kill them. L.A.'s Stand manifestation also seems to be the most combat-oriented of the family.
Not much is known about the Boomboom Family's life before the Steel ball Run. Benjamin mentions that Andre and L.A.'s mother left their home and became a whore.
Steel Ball Run
The Boomboom Family participates in the Steel Ball Run, aiming to be at the first, second and third place to maximize their gains. Lost in the mass of the racers during the first stage, the Boomboom Family assassinates three other competitors named Max Becker, David Hagen and Paul Lukather by using Tomb of the Boom 1 2 3 to magnetize them and make they collide.
During the second stage, the Boomboom Family follows Johnny Joestar and Gyro Zeppeli in the desert because of Oyecomova, who has put a bounty on Gyro. Andre is sent to trick them using the pretense of having been bitten by a poisonous lizard and soon enough Gyro kicks Andre's knife aside, magnetizing his leg. The rest of the family comes. L.A. forgets they have to disperse himself and his father yells at him for his stupidity.
Gyro's feet is invaded by steel and the duo realizes that they are dealing with enemies that are assassinating the competition. They realize that the Boomboom's ability is a magnetic power when Johnny's pistol is disassembled and the pieces are attracted to Gyro's feet. Benjamin Boomboom, the patriarch, destroys an incoming Steel Ball aimed at him with his magnetism. Andre's knife flies towards Gyro's neck but he blocks it. Circling the duo, Andre shows off some tricks that impress L.A. but refuses to reveal their secrets. Furious at Gyro for almost letting him die, Andre is the first to charge closer to Gyro. Gyro throws his remaining ball at a rock, making a piece of rock shoot through Andre. Seeing the Boomboom Family circle around them, Gyro understands that the magnetism is tied to his proximity to them and thus, the duo flees. As they move away from the Boomboom, the magnetisms weakens but Benjamin shoots through the hole in Andre, splashing some of Andre's blood on Johnny.
Benjamin, knowing he's followed by the cowboy Mountain Tim, manipulates pieces of metal into his face to make himself look like Johnny. Benjamin fakes surrendering to have Mountain Tim approach and throws his horseshoe at the cowboy, splashing some of his blood on him before crawling inside the briar patches. Mountain Tim reveals his ability Oh! Lonesome Me, allowing the cowboy to disassemble his body along his rope, and tries to grab Benjamin. However, Benjamin cuts the rope with a sharp piece of metal embedded in his face and escapes in the briar patches.
Mountain Tim catches up to Johnny and Gyro. As the family observes the incoming demise of their three enemies, Andre feels unwell because of his wounds and Benjamin leave him behind. However, Mountain Tim uses his power to tie himself to two rocks before he can collide with Johnny and Gyro. L.A. approaches and draws Tomb of the Boom 1 2 3 in the sand to summon it. He activates the iron sand and the sand binds all three horsemen. Mountain Tim shoots at L.A. but Benjamin protects him and Mountain Tim is bound by the sand. Tim collides with Johnny and Gyro but Johnny grabs a bullet, hoping to use the Spin with it. He creates a Spin, but Benjamin stomps his hand to deprive him of this weapon. Thinking himself victorious, Benjamin is taken by surprise when Johnny's nails spin and he shoots them, cutting Benjamin in half. Losing his mind, L.A. grabs Johnny and tries to kill him directly by extracting the iron in his arteries, but Johnny uses his spinning nails to vault above L.A. and cuts off his left toes. L.A. is also incapacitated and is left for dead in the desert.
Furious, L.A.. reveals to the trio that there's a bounty on Gyro's head and promises that Gyro will never reach the goal. L.A.'s ultimate fate is unknown.
- SBR Chapter 12: First Stage: Disqualified from Victory