Stuart makes his first appearance during the second season, where he works as the owner of The Comic Center of Pasadena.
Stuart connects with Raj in season 6 when Howard leaves for space. Single, lonely, and depressed, he often feels left out from the guys and looks for constant reassurance from them. He also deals with some financial trouble.
Kunal Nayyar as Rajesh Koothrappali – Then
Raj, an astrophysicist, has been on the show since season 1, where he played Howard’s BFF. He also used to spend all of his time hanging out in Leonard and Sheldon’s apartment, along with Howard.
During the first half of the series, Raj’s social anxiety was a major barrier to forming relationships with women. After the sixth season, he became more confident and began to date various women. In season 9, he even found himself caught in between two different women.
Kunal Nayyar as Rajesh Koothrappali – Now
Kunal is most known for his role as Raj in TBBT. However, he has done some other acting aside from the show. He starred as Tony in the movie "Dr. Cabbie" and played the voice of Guy Diamond in the DreamWorks animated film "Trolls."
He made $750,000 per episode, which really isn’t bad. He keeps acting, mainly in small roles, but hasn't done anything very big after the show ended.
Kevin Sussman as Stuart Bloom – Now
Kevin didn’t make his debut in TBBT. In 2001, he starred in Spielberg’s "A.I. Artificial Intelligence," playing the role of Supernerd.
The actor is financially successful, despite his character on the sitcom having financial issues. His income wasn't as high as some of the other costars; however, he still managed $50,000 per episode.
Alessandra Torresani as Claire – Then
Claire works as a screenwriter and bartender. She meets Raj and Howard at the comic book store. She wants Raj to write a script with her for a children’s science fiction movie.
Raj is into her, but Claire has no interest in him. Raj breaks up with Emily in order to pursue Claire, which only further repulses her. At one point, Claire does have an interest in Raj, who begins to date both Claire and Emily simultaneously, eventually breaking up with both women.