Lanna

Hucas is known as the friendship between Lucas Gottesman and Hanna Marin.

Season 1
"There's No Place Like Homecoming:" When Hanna joins Sean's abstinence club at school, "Real Love Waits," she finds a surprising ally in the equally reluctant Lucas. The members are asked to role play situations in which they would be pressured to have sex. Hanna is called to take a turn - with Lucas. Unenthusiastic, she pretends to ask Lucas to make out, and after initially refusing to play along, he then says "yes," making Hanna finally smile and Sean see red.

As yearbook editor in charge of photos, Lucas attends homecoming solely in order to photograph the event. At the dance, Mona and Hanna get into a heated argument when Mona makes nasty comments to Lucas, who has come to the dance as photographer for the yearbook. Hanna greets him warmly, but Mona shoos him away. After he leaves, the two argue over whether popularity is more important than befriending nerds.

Later, he gives Hanna a ride to the therapist's office so that she can steal Jenna's file. She keeps Lucas in the dark as to what she is doing, but he is happy to be hanging out with her. He confesses that besides for taking pictures, he had gone to Homecoming in order to elect Hanna Homecoming Queen.

The next day (in "The Homecoming Hangover"), he takes multiple shots of the homecoming king and queen, eventually frustrating the homecoming king with his suggestions, such as having Hanna sit on his lap. When Sean gets angry at Hanna, Lucas snaps a photo of Sean, roiling him further. Later, Lucas and Hanna have fun looking at online videos together, whereas Sean thinks the videos are stupid, proving how much more Lucas and Hanna have in common than her current boyfriend, Sean.

When Hanna decides to help out with the Marins' financial situation, she agrees to put up a lot of her old clothes and handbags up for auction online with the help of her new ally, Lucas, who gives her the idea in the first place.

Hanna and Lucas grow closer, as Lucas continues to score Hanna big bucks selling her lesser used accessories on the internet. But, Mona is not enthusiastic about this new relationship development and mercilessly taunts Lucas for not being manly enough. Later, fed up, Hanna pulls Mona aside and calls her a hypocrite for treating someone of lesser social status so heartlessly when they used to be on that same strata themselves! Later, Lucas thanks her for Mona’s improved treatment of him.

At the hospital after Hanna's accident, an attentive Lucas gives Hanna a sweet kiss as she sleeps. He brings her three choices of puddings when she awakens, trying to advance their relationship, but feels brutally rebuffed when she and tells him – in truth, that she sees him much more as a friend. He wishes that she would lie, rather than be so brutally disappointing, but she refuses. At Hanna’s homecoming party, Lucas drinks too much. Still upset from Hanna refusing to be more than friends, he makes a big scene. Later, he confesses to trashing Alison's memorial, though Hanna forgives him and promises to keep his secret under tabs. He was upset by the memories of Alison's terrible treatment of them all this time and finds it hard to understand why Hanna could ever be friends with such a mean person.

At the Dance-A-Thon, "A" instructs Hanna to repeatedly dance with Lucas and then break his heart, in exchange for her mother's money back. Sean is unforgiving of Hanna's unceremonious treatment of him after several dances with Lucas, leaving her to slow dance with him. At the end of the night, Lucas also feels rejected when Hanna turns down his offer to give her a ride home. Emily, though very drunk, catches onto Hanna's poor treatment of Lucas and comments that Alison would be proud. Hanna feels very remorseful.

In "For Whom the Bell Tolls," Lucas is suspicious of Mona and what she had to do with Caleb leaving town. Mona tries to intimidate Lucas to forget about it, tempting him with the prospect of obtaining Hanna, but Lucas clearly doesn't take the bait, as later we see Lucas and Caleb in a car together! Lucas is driving Caleb back to Rosewood, Pennsylvania (from Arizona?).

Season 2
When Lucas and Caleb arrive in Rosewood, Lucas protectively warns Caleb not to hurt Hanna again.

When Hanna is no longer allowed to see her friends, she decides to help Lucas with the yearbook. At first, Lucas wonders why Hanna is being so nice to him, worried that she has ulterior motives—but Hanna insists that people can change. She even gets a pretty girl named Danielle that Lucas is so obviously crushing on to agree to a date with Lucas.

In "Blind Dates," Lucas is nervous about his upcoming date with Danielle, so he asks Hanna to double with him and tells her to bring Caleb. Unfortunately it backfires, as Danielle thinks that Hanna is interested in Lucas. To convince Danielle that there is no longer anything between her and Lucas, Hanna recruits Caleb to better pretend to be on a real date and in a romantic relationship with each other. It works, and Danielle reaches for Lucas' hand. Lucas now understands Hanna's motives to be pure. He thanks Hanna later for helping him with Danielle and acting so un-Alison like. Lucas' words play a major role in helping Hanna get over Alison and the effect her bullying had on her self-esteem.

Hanna and Lucas' friendship seems to have grown strong during the month between "Over My Dead Body" and "Through Many Dangers, Toils, and Snares." He has been helping her take down all the unflattering community service photos of her that have surfaced on the internet. He tells her she looks pretty despite her protests. There is tension between Lucas and Caleb over Caleb's plans for the future and potential for hurting Hanna.

In "A Hot Piece of A," Lucas reluctantly helps Hanna study for a test and plan Caleb's surprise party. It seems he is hiding a big secret from Hanna, even calling a crisis hotline to get it off his chest. Emily and Spencer try to convince Hanna that Lucas is A's helper, the one that tried to kill Emily in the greenhouse, but Hanna refuses to entertain the idea without proof. Lucas and Hanna take the rowboat from Spencer's lake house to the other side of the lake to set up fireworks. Lucas stops rowing half-way across so they can talk. Hanna gets spooked and pushes Lucas out of the boat.

In "Let the Water Hold Me Down." after the incident, Hanna tells the others she is sure Lucas is still alive. The next day she finds out from Lucas' parents that he called them and is staying with a cousin for the time being. Caleb, however, doesn't buy it and wants to search for Lucas. Hanna isn't quite as eager because she is afraid Lucas could have been helping "A," but can't tell Caleb that. That night, Hanna notices the wind blew the door open, and thinks the latch is broken, but really Lucas broke in to the house.

Lucas slips into Hanna's bedroom while she is in the hall talking to her mom. He surprises her there, claiming that he never wanted to hurt her. Hanna asks what he did to Caleb while covertly calling Caleb on her cell. Caleb, who is already downstairs, gets the call and rushes up to Hanna's room, hearing Lucas' threatening voice in the background. Caleb asks what Lucas did and where he has been. Lucas reveals why he was on the hotline: He lost $4,000 in a bet over a basketball game, money which belonged to Caleb. It was a sure thing until the team got disqualified. After the rowboat incident, he drove all over selling his comic books to try to get some of Caleb's money back. Now they're all on good terms again, but Hanna now is unsure of who they met in the greenhouse.

Season 3
In She's Better Now Hanna is worried about Lucas when Mona whispers something to him but he doesn't say anything to her. The next day Lucas knocks on Hannas door with the last of the money he owed Caleb. Hanna asks him about his leg and he says that he got in a skateboarding accident. Hanna asks Lucas what's going on between him and Mona but he says nothing, apart from telling her that Mona had been sneaking out of Radley Sanitarium for a long time, and he won't say why.