Raj Koothrappali is an Indian-born astrophysicist who lives in Pasadena and works at Caltech. Until recently, Raj was unable to talk to women due to his selective mutism. Raj usually needed a beer in his hand before he could even talk to the girls, including Penny with whom he had a one night stand of sorts.
Raj was born in New Delhi, India, the son of a wealthy gynecologist. Although Raj has tried to play down his family's wealth, Sheldon has seen notarized proof that the Koothrappalis are vastly wealthy - Richie Rich rich. During his childhood, Raj's parents employed a number of servants and his dad drove a Bentley. Raj has four siblings including Priya, his sister who dated Leonard. Before moving to Pasadena, Raj completed some of his education at the University of Cambridge, where he fell in love with astrophysics.
Raj's parents often contact him via video chat from their home in India. Raj had talked about how his parents were in a loveless marriage and recently his got parents divorced. Raj's father visited Pasadena for Christmas 2014 following his divorce.
Raj's fashion style usually includes sweater vests, khakis or cargo pants. Apart from his familiar purple jacket, many of Raj's clothes are in olive green or mustard yellow color. Despite being proud of his Indian heritage and culture, Raj is not a fan of Indian food, unlike the rest of the gang.
With his balls-to-wall moisturizing regime and his love of "chick" flicks and literature, Raj's metro-sexuality has been a long running joke. Despite this and his very close friendship with Howard, described by Beverly Hofstadter as an ersatz homosexual marriage, Raj has insisted he likes women and their skin care products. Being unable to talk to women sober for a long time, Raj struggled to start proper relationships - though he seemed to "get lucky" more often than the other guys.
Raj has admitted he was lonely when he first moved to America, but this changed when he met Howard as they could be lonely together. Raj has spoken fondly of Mrs. Wolowitz who welcomed him into her home when Howard was his only friend.
From the beginning, Penny had a soft spot for Raj, even though he couldn't speak in her company - at least not without a beer for six years. Penny accompanied Raj to the People Magazine banquet when he was included on their 30 Under 30 To Watch list, though Raj's drunkenness spoilt their night. His friendship with Penny was almost ruined when they had a one night stand, of sorts, at the end of the fourth season. After Raj admitted to Penny that they didn't actually have sex, the pair patched things up.
Despite Howard being his best friend, Raj did have an infatuation with his then-girlfriend Bernadette and wrote crude poems about them. When Howard and Bernadette got engaged, Raj's feelings eventually subsided. Given his closeness to Howard, Bernadette has spent a lot of time with Raj and has often tried to help him with his relationships. Howard and Bernadette got Raj a dog, Cinnamon, to keep him from being lonely. Raj's close relationship with his dog has raised eyebrows, as did his "relationship" with the iPhone's virtual assistant, Siri.
When Howard was in space, Raj formed a close friendship with Stuart, who moved into Raj's apartment. Raj has helped Stuart throw parties at the comic book store. They both signed up for an online dating service together and went to a mall to try meet women.
Dr. Koothrappali is an astrophysicist at Caltech. When he discovered a planetary object beyond the Kuiper belt, 2008 NQ17 (which he nicknamed Planet Bollywood), Raj was included in People magazine's "30 Under 30 To Watch".
When Raj's research into trans-Neptunian objects came to an end, his working visa expired and he was threatened with deportation. Raj tried to take another job at the university, but the presence of a female professor required him to drink during the interview, leading to him making inappropriate comments. Sheldon offered Raj the option of working for him. Raj eventually accepted Sheldon's job offer, though working for him was not easy.
Although Raj's selective mutism didn't stop him from having a few one night stands, he was generally unable to start a lasting relationship with a woman. When Sheldon's sister, Missy, visited, Raj was able - with the help of experimental drugs - to charm Missy, but his chances with her fizzled out when the drugs wore off. Raj had a short-lived relationship with a deaf woman, Emily, who was only using him for his family's money.
When Raj helped Stuart throw a Valentine's Day party at the comic book store, Lucy approached Raj and the pair went out for coffee. Raj fell into a depressed funk after Lucy climbed out of a bathroom window at the coffee shop. When Lucy explained her social anxiety to Raj, he agreed to meet up with her for a proper date. Raj decided their first date should be a silent "texting date" in a local library.
After Raj and Lucy had been dating for a few weeks, Raj wanted Lucy to meet his friends, but she was nervous of meeting the whole group. Raj chose for her to meet Amy one-on-one, but after they started bickering about Lucy's social anxiety, she locked herself in the bathroom. Raj talked Lucy into attending a party at the apartment where she could meet the whole group, but on the night of the party she text him to say they shouldn't see each other any more.
Lucy dumping Raj was the catalyst for him working through his selective mutism. The night after Lucy dumped him, Penny stopped by Raj's apartment to check on him. As Raj told Penny how he felt unlovable, Penny said it was just the booze talking, but Raj revealed he hadn't drank since the night before. Although Penny cried when Raj could talk to her, the girls were soon wishing he would shut up.
When Emily contacted Raj on a dating site, he didn't want to come on too strong so he had Amy write a message to Emily. After chatting with Amy, Emily decided she didn't think she was right for Raj as he was too shy and passive. When Raj interrupted Amy and Emily at a coffee shop, she thought he was weird and lacked boundaries. However, when Raj later ran in to her by chance at a coffee shop, they agree to go out on a proper date.
When Raj and Emily had a double date with Howard and Bernadette, Emily realized she once met Howard before when he clogged her toilet and climbed out her bathroom window, nicknaming him "Clogzilla". Emily's dark side, which includes watching gruesome horror movies, has concerned Raj, though she looks past it.
Raj's close relationship with both Emily and Cinnamon led Howard to invent a game "Emily or Cinnamon?", in which players must decide whether a creepy statement from Raj was about his girlfriend or dog.
Raj: Okay, here we go.
(To Leonard & Penny) Say cheese.
(To Sheldon & Amy) Say cheese.
(To Howard & Bernadette) Say cousin.
Howard: You know, when I was a kid I loved going there but I could never get a ride.
Raj: Ooh, what if we got a van and drove around, and picked kids up?
Sheldon: Nice! Like at parks and schools.
Howard: Toy stores, puppet shows.
Leonard: Hold on, so your idea is to get a van and cruise the streets looking for kids to pick up?
Leonard: And are you going to use candy to lure them in?
Raj: We are now!
Raj: I'm sorry I'm so late. I was on the phone with my mother.
Bernadette: How is she?
Raj: Pretty good. She bought the book "Eat, Pray, Love", and used it to set my father's Mercedes on fire.
Raj: Oh man, first monster I see I'm gonna sneak up behind him, whip out my wand and shoot my magic all over his ass!
Stuart: Do you hear yourself when you say these things?
Raj: I've said this before and I'll say it again: Aquaman sucks!