Stuart David Bloom is the owner of The Comic Center of Pasadena, which the guys regularly visit, and their friend. He has a talent for drawing and is a graduate of Rhode Island School of Design. He also has an extensive knowledge on comic books and first appears in the season 2 episode "The Hofstadter Isotope". He also acts as the competition when he dated Penny Hofstadter and Amy Farrah Fowler to help move other's relationships forward.
Stuart starts bonding with his similarly lonely counterpart Rajesh Koothrappali at the start of season 6, substituting for Howard Wolowitz when Howard has gone to space. He often seeks approval from Sheldon and his group. His actor, Kevin Sussman, was added to the main cast in season 6 with his credit at the opening when he was present in the episode; however, he was demoted back to the recurring status in "The Tangible Affection Proof" (S06E16), but had it restored at the start of season eight in "The Locomotion Interruption". As of September 2015, Stuart has appeared on more episodes than Mrs. Wolowitz and is right behind series regular Amy.
He is helpful and kind-hearted, but due to his overworking schedule and underpaying job as comic book shop owner, he isn't able to get out much and often gets depressed and struggles financially.
Stuart Bloom is an slender man with fair skin, short brown curly hair, brown eyes. He wore an jacket, shirt, Pants and shoes in various colors.
Stuart's first appearance was "The Hofstadter Isotope," where he asked Penny out on a date, not knowing Leonard had feelings for her. The date itself went fine, but the end was interrupted by Sheldon. The two debated about who would replace Batman if he should die. Penny falls asleep as they argue, and the two leave.
He has a second date with Penny later in "The Classified Materials Turbulence" and asks Leonard for advice on how to approach Penny. Leonard deliberately avoids Stuart's request and ultimately gives him bad advice. The next day, Leonard feels guilty and goes to apologize to Stuart. Stuart reveals the date went really fine, until he and Penny started making out in his car and Penny accidentally called him "Leonard." He understands she and Leonard have unresolved feelings, however, and holds no anger towards Leonard.
In "The Guitarist Amplification," Sheldon goes to the comic book store to avoid Leonard and Penny's bickering, which he hates. The two arrive to get Sheldon, and it appears Stuart still harbors some feelings for Penny, despite her and Leonard having started dating (he whispers, "I love you," when she walks away).
In "The Creepy Candy Coating Corollary", Sheldon enters a collectible card game tournament only after he hears that Wil Wheaton, for whom he harbors a deep resentment for missing a 1995 Sci-Fi convention, is also participating. With Raj as his partner, they reach the final match against Stuart and Wil. Sheldon can easily win, but Wil lies, claiming his grandmother's death prevented him from appearing at said convention, which tugs at Sheldon's heart-strings. Sheldon lets Wil win, leaving Sheldon even more resentful of him after Wil tells him the truth that his grandmother is still alive. Stuart is, of course, pleased about their win.
"The Wheaton Recurrence" sees Stuart pairing up with Wil and a few guys from the comic book store to compete against the guys and Penny in bowling. His team wins by default because Penny leaves after Wil (once again) manipulates the other team by convincing her to not string Leonard along. The episode folds with the four guys walking into the comic book store dressed like Catwoman (Raj), Batgirl (Howard), Wonder Woman (Sheldon), and Supergirl (Leonard), since they lost the bet to Wheaton and Stuart.
In "The Desperation Emanation," Stuart states he is dating a girl he met at a comic convention. Though he does not like her, he continues to date her because he does not want to be alone.
He hosts his annual costume party for New Year's Eve in "The Justice League Recombination."
In an attempt to replace Leonard, Howard and Raj as friends, Stuart is invited over by Sheldon in "The Toast Derivation", along with Barry Kripke and Zack Johnson. Stuart takes advantage of the invitation to take a hot shower in Sheldon's bathroom and ends up singing karaoke with Kripke and Zack.
When an attractive girl named Alice enters the comic book store, Stuart tries and fails to ask her out, though she gives her number to Leonard to trade for the comic book Leonard is preparing to buy. Even though Leonard has not exactly picked up a girl in the store, Stuart still takes a picture of him to be put up on the "Wall of Heroes".
When Amy visits the comic book store with Sheldon, Stuart, after inquiring about the state of her relationship with Sheldon, asks her out in "The Flaming Spittoon Acquisition". When Sheldon later learns that Amy and Stuart are out on a date, Sheldon becomes jealous and asks Penny to go out on a date. After talking to Penny, he interrupts Amy and Stuart on their date, and asks Amy to be his girlfriend, which she gladly accepts. Stuart takes her home anyhow, understanding and accepting the situation.
Sheldon tries to chitchat with Stuart when he needs someone to take him to the dentist in "The Friendship Contraction". Stuart tells Sheldon his shrink just killed himself and blamed Stuart in the note. Stuart also mentions that his parents are alive but his grandparents are not.
He goes to Howard's bachelor party and makes it clear he is still financially strapped in "The Stag Convergence".
Starting in season 6, Stuart is promoted to a full cast member so as to provide a friend for Raj since Howard is married and is away at the International Space Station. Their interplay is similar to Raj and Howard's friendship though he makes more comments like "does he know what he's saying" than Howard did. He gets accepted into the main group with Sheldon calling him "the fake Wolowitz". By "The Re-Entry Minimization", Stuart has moved in with Raj.
In "The Bakersfield Expedition", Stuart hosts Penny, Amy, and Bernadette at his comic book store during their venture to find out why their guys like comic books.
In "The Tangible Affection Proof", Stuart and Raj put together a party for people who had no one on Valentine's Day, which was better than the suicidal feelings he would have had if he had been alone that night.
In "The Deception Verification", Stuart uses reverse psychology to make Sheldon not only buy, but pay a severely increased price, for an Aquaman figure and a squirt gun. Sheldon willingly pays $1200 for the Aquaman figure and $200 for the squirt gun.
Stuart allows Raj to use his comic book store for the scavenger hunt in "The Scavenger Vortex". Whilst Raj is in the store, Stuart asks if the social group ever thinks about inviting him to hang out with them. He is disappointed when no one buys anything.
In "The Occupation Recalibration", Bernadette comes to the store to replace one of Howard's comic books that she destroyed. Stuart takes her to a rival store owned by an obnoxious guy named Jesse who keeps taunting Stuart. Bernadette stands up for her friend. Stuart also finds his friend Captain Sweatpants hanging out at Capitol Comics.
In "The Status Quo Combustion", the comic book store has suffered a fire. Stuart is despondent about how to make a living, unsure of what will happen with the insurance payout. Howard offers him a job taking care of his injured mother, which turns out to be fun for Stuart.
As of "The Locomotion Interruption," Stuart is re-promoted to a regular cast member. Stuart is still living with Debbie Wolowitz, in spite of her recovery, and he starts to share a bond with her which Howard finds disturbing, as they even share an answering machine recording. Later, Stuart arrives at Howard's house to talk about what is going on, but it quickly descends into an argument in which both men accuse one another of trying to act like the other's father.
In "The Hook-up Reverberation", Raj tells the gang that Stuart didn't get enough insurance money to reopen his store. The guys decide to give him the money and were enthusiastic about owning a comic book store. Mrs. Wolowitz beats them to it and gives Stuart the money.
In "The Prom Equivalency", Howard is worried that Stuart will bring his mother to their prom party. Instead he shows up with Howard's second cousin Jeanie whom he had lost his virginity to at a funeral when he was fifteen in the back of her father's Toyota Corolla. They try to get him to forget it since it was long ago; however, Howard eventually loses it and starts choking Stuart in the limo on the way to the party/
In "The Comic Book Store Regeneration", Stuart reopens his store which bothers Howard because she gave him the den furniture from her house to use at the store.
In "The Leftover Thermalization", Stuart tells Howard that the electricity has been out for hours and Howard is devastated that he'll lose all of his mother's food that was in the freezer. The whole gang has one last meal cooked by Mrs. W. In later episodes he is still living there after Howard and Bernadette clean out the house and move in.
In "The Commitment Determination", Howard and Bernadette want Stuart to move out of their house. Howard wants Bernadette to break the news to him, but they can't because they learn that it's his birthday so they serve him a cupcake with a candle in it rather than serving him an eviction notice.
In "The Matrimonial Momentum" Stuart is still living with Howard and Bernadette. He and Howard are the only ones of the gang to catch the 'I now pronounce you Husband and Wife' bit of Leonard and Penny's wedding. He later tries to take advantage of Amy and Sheldon's break-up by bringing to the attention of Amy that there are other men out in the world, while placing his hand on her shoulder. The advance was not received well. He also lit up when hearing that Penny and Leonard had a fight after their wedding, and Penny was in her apartment alone.
In "The Perspiration Implementation", the girls try to help Stuart attract more women to his store. Stuart has stocked more women friendly comics and put in a breast feeding section which a webcam for protection though the girls find it creepy. Finally everyone including Stuart decide that he is the problem, though he admits that he is getting desperate. Amy tries to console him since she used to feel the same way. Stuart just thinks that she wants him to ask her out.
In "The Sales Call Sublimation", Stuart finally moves out into his own apartment. Though they don't want to admit it, Howard and Bernadette miss him.
He will appear in the 200th episode as a guest at Sheldon's birthday party.