Rajesh Koothrappali had one of the most transformative character arcs in The Big Bang Theory. A once shy and nervous man who couldn't talk to women, Raj grew both professionally and personally. While Howard took advantage of Raj's kindness from time to time, he really grew to stand on his own two feet by the end of the series.
The sitcom showcased all of the main characters' romantic lives, but Raj's romances were the star of his storylines. All he wanted to be was a husband and later, a father, but he couldn't find the right match. All the while, he focused on his friendships and job as an astrophysicist at Caltech. Along the way, Raj grew into a more mature and authentic version of himself by season 12.
Season 1: His Way Around His Selective Mutism
Season 1 was the only time viewers saw Raj sporting a hat. After this, he stuck to straightening his hair and keeping his style the same.
When Raj, Howard, Sheldon, and Leonard met Penny, Raj was as blown away by Penny's beauty, as were the rest of the guys. Unlike his friends, however, Raj had a secret: he had selective mutism where he wasn't able to speak to Penny (or girls in general). In the middle of the season, Raj found out he could speak to women, as long as he had a few sips of alcohol to make himself comfortable.
Season 2: Howard's Go-To Wingman
In season 2's "The Griffin Equivalency," Raj's career was on a high when he was selected as one of "30 Visionaries Under 30 Years Old to Watch" by People Magazine.
His personal life, on the other hand, was suspect while looking for women in his spare time with Howard. It became even clearer in season 2 that Raj and Howard were each other's go-to for all things fun, work, and relationships.
Season 3: Raj Becomes Closer To Sheldon
In season 3's "The Pirate Solution," Raj is terrified when his work visa is about to expire and he could face deportation. Raj loved his life in America with his friends and didn't want to go back to India quite yet. Luckily for him, Sheldon came to the rescue and hired him.
Working next to Sheldon made Howard busier but made Sheldon appreciate him more after he felt left out by Howard's constant need to chase women. The two made up, of course, and by the season finale, Raj and Howard found the perfect match for Sheldon, a scientist named Amy Farrah Fowler.
Season 4: Lonely & Desperate
In season 4, Raj becomes lonely and jealous when Howard begins dating Bernadette. Not only did Raj miss spending time with Howard, but he also was secretly crushing on Bernadette. To make matters harder for Raj, Leonard began dating Raj's sister, Priya.
Raj felt excluded. By the end of the season, Sheldon encouraged Raj to try medication to help with his social anxiety, and while it didn't go as smoothly as Raj would have liked, he did end up spending the night with Penny, which caused some major drama in the friend group.
Season 5: Guys Nights Were A Thing In The Past
At the start of the season, Raj is still in an uncomfortable situation with the group after spending the night with Penny. But they were able to move past it when Penny set Raj up with a friend of hers, Emily.
The relationship didn't last long, but Raj threw his entire being into it while it lasted. He later focused on his friendships but alas, he felt alone. In "The Weekend Vortex," Raj made the group realize that they never have guys' nights anymore because everyone has girlfriends. His rant made them realize how much has changed among the group.
Season 6: Raj Falls For Lucy And Gains Man's Best Friend
In season 6, Raj began spending more time with Stuart after Howard married Bernadette and went to space. It was because of a joined Valentine's Day party at the comic book store that he met Lucy.
The two began dating in season 6 but the two fell apart when Raj was too pushy. To make up for his heartbreak, Howard and Bernadette gifted Raj a dog named Cinnamon.
Season 7: The Raj & Emily Era Begins
Raj focuses on his friendships and getting back on his own two feet after breaking up with Lucy. He and Stuart attempt to start fresh by joining a dating app, but realized it was a bad idea when women looked at their profiles but weren't interested.
Raj eventually finds another woman named Emily Sweeney, who rejected him at first but later found him charming. The two had a subtle but sweetly memorable first date because of how honest he was with Emily. Season 7 was the start of something new for Raj.
Season 8: His Parents' Divorce Affected Him More Than He Realized
At the start of the season, Raj introduces everyone to Emily but she doesn't get along with Penny, Amy, and Bernadette right away. Considering they had such a tight-knit group, this was strike one. By the end of the season, Raj began to wonder if he and Emily were compatible at all because she had darker interests than him.
Outside of his relationship, Raj's bond with his parents becomes tainted when he finds out they're getting a divorce. He turns to religion for clarity and later surrounds himself in work when he begins working on a project for NASA in "The Communication Deterioration."
Season 9: The End Of Emily And The Start Of Becoming An Uncle
In "The Sales Call Sublimation," viewers got to see Raj at work when Sheldon joined him in the astronomy lab. The two discovered an asteroid and had the honor of naming it. But his work is overshadowed when a woman named Claire enters his life.
After meeting Claire, Raj realized that he wasn't as in love with Emily as he thought he was. He broke up with her and tried starting something with Claire. When that didn't go the way he was hoping, he threw himself into Bernadette and Howard's pregnancy and prepped himself to become an uncle.
Season 10: Raj Focuses On Himself And Becomes Independent
With Bernadette gearing up for her first baby, Raj was a big part of her preparation. He helped her and Howard with the nursery, breathing techniques, and did things around the house. Now that he was single, he put all his effort into helping his friends and bettering himself. In "The Emotion Detection Automation," Raj brought his four exes together so that he could get to the bottom of why he was a bad/good boyfriend. The meeting was a revelation for Raj, who decided to start fresh.
After years of living off his parents' allowance, Raj became financially independent from them and moved in with his friends until he could get back on his feet.
Season 11: Raj Focuses On His Career And Takes A Step Back From Howard
Raj helps out the Wolowitz family yet again in season 11 when they found out they were pregnant with their second baby. In the meantime, he interviews for a job at the planetarium and is disappointed when he blows it. His dad claimed it was because of his lack of confidence, and this was largely because of Howard.
Raj agreed that Howard had villainous tendencies and began to work on his belief in himself and took a step back from his friendship with Howard. From doing that, he excelled both at Caltech and at the planetarium.
Season 12
Season 12 Raj is vastly different from season 1 Raj, He transformed into a butterfly over those 12 years and was better for it. He learned about relationships, become financially independent from his dad, and worked on himself to find out what he really wanted in life.
After spending season 11 focusing on himself, he spent season 12 trying to make a marriage with Anu work. But towards the end of the season, he realized Anu wasn't the one for him and he wasn't willing to put his heart on the line. Although he was the only one without a partner, in the end, he was arguably the most secure in himself.