He attended Duel Academy and was put in the Slifer Red Dorm, the dorm with the least privileges, due to his poor grades in the entrance exam. As time goes on, he becomes the academy's best Duelist and saves the world and the academy from many threats such as the evil Kagemaru, The Light of Destruction possessed Sartorius, the deranged and manipulative Yubel, and finally the malicious spirit Nightshroud. After three years, he graduates from Duel Academy and pursues his own journey to improve himself.
Personality-wise, they seem like total opposite. Makoto is a smart introvert, Jaden is a prodigious & skilled, book dumb introvert.
I guess they have the commonality of being able to see spirits & using monsters?
In his past, Yubel, then his favorite card, was... overprotective, & often engineered the deaths of his opponents after duels, as well as anyone who'd dare make him sad. The 1st time this happened, it was to a good friend, & Jaden went into a coma. No one would duel him, but he cherished his favorite card too much to throw it away.
Jaden later won a KaibaCorp card design contest... & got to have his 2 cards (& by his request, Yubel.) sent into space. KC wanted to expose them to "space waves". Yubel was exposed to the Light of Destruction, & sent pleas for help, which he received as nightmares, depriving him of sleep from terror. Young Jaden was soon treated for this by a medical procedure that blocked the visions & made him lose memory of this history.
In Season 2, after a loss to Aster, Jaden loses the ability to see his cards, gets on a boat... & ends up sent a place called Dolphina in Neo Space (A Duel Monsters Spirit World.) that is also apparently an uncharted planet near Jupiter. A talking, anthropomorphic dolphin card spirit pep talks him, & an evil alien robot serving evil alien light tries to kill them both, then Jaden can see his cards again, & also he has the Neo-Spacian Archetype now. (Plus Neos, his new ace.)
He later beats a mind controlling apocalypse cult who's boss uses a Tarot-themed deck.
A major character point for Jaden is in Season 3, where a rescue attempt into an Alternate Dimension (Which is a whole arc.) prolongedly makes little progress on finding Jesse, Jaden's new best friend (Same personality, & they could perceive each other's Duel Monster Spirits.), while his other friends were in danger.
He couldn't enjoy dueling because all his friends were dying & multiple universes' fates were at stake & doubts how he's been living is right. He develops The Supreme King alter ego or it brainwashes him (I'm unclear on that.) & becomes the evil overlord. Slaughter, hunting people down, etc.
Season 4 wasn't localized, & involves soul searching, & a villain of darkness named Trueman, IIRC.
At the end, Jaden duels Yugi. We see most of it, but the ending is left unshown; We cut from an inconclusive moment to Jaden in the desert, who's resolved to continue his journey.
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