Rai is a Final Fantasy character that appears in Kingdom Hearts II. He originated from Final Fantasy VIII as the character Raijin. He is a member of the "Twilight Town Disciplinary Committee" led by Seifer, along with Fuu and Vivi.
Rai isn't terribly bright, but that's not too much of an impediment since his main role in the gang is to toss his considerable weight around. He's got an infamous habit of ending sentences in "y'know", which is joked about in Jiminy's Journal.
Rai is never seen without Fuu.
 Kingdom Hearts II
On the 1st Day in the simulated Twilight Town, Roxas and company confront the Committee, who have been claiming they stole photographs from people all over town. Rai watches Roxas and Seifer's fight with the rest of the Committee. If Roxas wins, Rai defends Seifer, saying that he's not feeling well; if Seifer wins, Rai taunts the others.
On the 3rd Day, Roxas is chased by Dusks into the Sandlot, where the Committee is hanging around. Dusks surround them, but they are suddenly frozen in time. After Roxas comes to after he talks to Naminé, Rai is praising Seifer for driving the Dusks off, and he shouts after Roxas not to forget the Struggle tournament.
During the tournament on the 4th Day, Rai cheers for Seifer to win. After Seifer is beaten by the fake Vivi, Rai and Fuu follow him from the Sandlot.
When Roxas and Pence arrive at Sunset Station on the 5th Day while investigating the Seven Wonders, Pence tells Roxas that Rai had started a rumor that the steps to the station count differently up and down when he simply was counting wrong.
When Sora and company return to Twilight Town, they find Seifer, Rai, and Fuu in the Sandlot, having been overwhelmed by a swarm of Nobodies. After the swarm is defeated, Seifer gives Goofy his trophy and leaves with Rai and Fuu.
Some time after Xemnas's defeat, Rai cheers Seifer on during a Struggle tournament fight against Hayner.
Rai's appearance, like most Final Fantasy characters in the Kingdom Hearts universe, was altered from his original in-game appearance as "Raijin". As with Seifer and Fuu, Rai now appears several years younger than he did in Final Fantasy VIII. He has tan skin and short black hair, somewhat shorter than his original appearance, albeit with longer sideburns. For his age he is tall and very muscular. His clothes now consist of an orange tank top and baggy dark sweatpants over wide shoes, giving him the look of a basketball player. Around his neck, he wears a thunderbolt necklace as an homage to his name's origin and his elemental affinity in his original appearance. His orange tank top also sports two thunderbolts on the upper back near the arms. The number 8 on his pants may be a reference to the Final Fantasy installment he appeared in.
Raijin is also the name of the Japanese god of thunder, which fits Raijin's use of thunder-based attacks.
Rai is loud, brash, and tries to exude a manly attitude. He is very loyal to Seifer, and does anything Seifer asks. However, he isn't very bright, so he relies on his strength and is easily angered. As part of the Disciplinary Committee, Rai often bullies others, especially Roxas and Hayner's group.
A defining piece of Rai's personality is how alludes to his original character in Final Fantasy VIII, by ending his lines with "y'know." Raijin in Final Fantasy VIII often finished his lines with "ya know."
Raijin is a character from Final Fantasy VIII. He acts as Seifer's lackey, along with fellow Disciplinary Committee member Fujin. The two of them follow and support Seifer unconditionally, even after Seifer goes rogue and leaves Balamb Garden to serve Sorceress Edea. However, when Seifer resurrects Lunatic Pandora, he and Fujin beg Seifer to stop following this path and return to being their friend.
Raijin often comes off as rather stupid, and he tends to end his sentences with "ya know?"