Stuart Bloom

Stuart Bloom is the owner of The Comic Center of Pasadena which the guys often visit. He has a talent for drawing and is a graduate of Rhode Island School of Design. He also has an almost encyclopedic knowledge of comic books. He was only added to the main cast in season 6 when his credit was added to the episode opening.

Season 2
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 gets another 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.

Season 3
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 Wheaton. 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, pleasant about their win. "The Wheaton Recurrence" sees Stuart paring 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.

Season 4
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.

Season 5
When an attractive girl named Alice enters the comic book store, Stuart tries and fails to ask her out, though Leonard gets a "date" with her (he is still dating Priya Koothrappali at this time, so his intentions were innocent). Nevertheless, Stuart takes a picture of him as an honor. When Amy visits the comic book store with Sheldon, Stuart, after inquiring about the state of her relationship with Sheldon, asks her out. 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. He goes to Howard's bachelor party and makes it clear he is still financially strapped.

Season 6
Starting in season six, Stuart is promoted to a full cast member to partially provide an unmarried 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. He is the oldest member of The Social Group.

Season 7
In "The Deception Verification" Stuart uses reverse physcology to make Sheldon not only buy, but pay a severly 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 he asks if the social group even think about inviting him to hang out with them. He is disappointed when no one buys anything.

Trivia

 * Stuart's family name Bloom is revealed on his Facebook page in The Flaming Spittoon Acquisition (S5E10) when Sheldon is examining this page.
 * Stuart has twice developed a crush on a love interest of a main character. The first was Penny (Leonard), then Amy (Sheldon). Ironically, in both cases, he unintentionally helps the characters' relationships grow.
 * The only season Stuart does not appear in is the first.