Logan Huntzberger is Rory Gilmore's serious boyfriend in the last seasons of the series.
Logan is the son of Mitchum Huntzberger, a successful newspaper magnate. Logan attended a variety of boarding schools in Massachusetts such as Groton, Rivers, Exeter, and Andover where it is presumed that he graduated. The Huntzberger family is what can be described as "old money". It is shown that his father loves Logan but at times treats him more like an heir than his son. His mother Shira tends to be snobby even though she doesn't come from "old money" herself. Logan and Rory Gilmore met while attending Yale. Both Rory and Logan worked at the Yale Daily News. Logan's appearance in the news room was uncommon and an annoyance to Doyle McCaster, the editor of the Yale Daily News. Doyle sucks up to him in the thought that he might meet Logan's father. Logan often refers to Rory as "Ace" because she wants to be a reporter. The nickname eventually becomes a sweet term of endearment. Rory enlists Logan's help on a article about a secret society, to which Logan belonged, called the Life and Death Brigade. He agrees to help her leaving clues around her suite. Logan takes Rory to a secret event party in the woods (5.07). Through that event, Rory becomes fascinated with Logan. She sees him in a different light after seeing how the other members treated him. Logan convinces Rory to take a dangerous jump with him. The jump strengthed the trust between both of them.
After this, Logan and Rory's start developing a tentative friendship with Logan comforting Rory at a party her grandparents threw for her where Dean broke up with her. They partied together in the pool house of Rory's grandparents house, with Logan's friends, including Collin and Finn.
Collin bursts into one of Rory's classes pretending to pledge his love for her and then Logan comes in, the two pretend to fake fight as a prank, but Rory gets him back by enlisting her grandfather to trick him and his friends into thinking that Logan's parents and Rory's grandparents were planning for their wedding. Rory soon develops a crush on Logan and admits it at her grandparents vow renewal. Logan admits he likes her back but is not a commitment guy. Later that night, Rory and Logan were caught hooking up in a back room during the vow renewal. Rory and Logan agree to a no-strings relationship that lasts until mid S5 when Rory realizes that she can't do it and wants to be friends again. However, Logan takes it as an ultimatum and the two of them start dating. Rory is Logan's first serious girlfriend, except for when he was ten and claimed actress Alyssa Milano held the position, due to a, "weird 'Who's the Boss?' phase," as revealed by his sister Honor. Rory and Logan's relationship survives many hurdles, first his mother's and grandfather's disapproval of Rory because she wants to work rather than stay home and plan parties. However, Logan does not pay heed to what his family says and still stays with Rory. Logan also comforts Rory when his father says that Rory is not cut out to be a journalist. Logan supports Rory when she decides to take a break from Yale even though he believes that she will eventually come back to Yale.
During Rory's break from Yale, Logan help keeps her distracted by involving her in his hedonistic life style, often flitting the bill. When Jess visits Rory at her grandparents' house the worst of Logan's entitlement and pompousness come to the fore. He verbally berates and tries to goad Jess into a fight, which doesn't work but does cause Rory to reevaluate to her life and their relationship.This leads to a break, which Logan perceives as a break up. Eventually he uses a series of increasingly thoughtful grand gestures such as massive amounts of flowers to apologize and win Rory back.
After having a disagreement with Rory over Logan technically "cheating" on her while they were on their "break", he goes to South America to do a stunt with the Life and Death Brigade. Logan suffered a grievous injury during the trip with The Life and Death Brigade and is flown to a hospital in New York. When Rory finds out where he is, she rushes over and is very worried. While Logan's in the hospital, Rory realizes how wrong she was to be mad at him, and Logan admits that he should have handled the situation better. After a conversation with Logan's older sister Honor, Rory learns that Logan's father, Mitchum Huntzberger, was purposely avoiding Logan in the hospital due to his disapproval of Logan's participation in the Life and Death Brigade. Rory, then, calls Mitchum and tells him that she "disapproves" of his behavior. This phone call from Rory makes Logan's father come down to the hospital, which cheers up Logan to see that his father cares about him.
Logan had been strongly encouraged, even forced, by his father to enter the family business. And, finally at the end of season six, Logan moves to London to join his family business. Rory throws him huge goodbye party and tries to go to the airport with him but he said that if she went he wouldn't board the plane. Surprisingly, after the conflict he suffers with his father earlier, he takes his new responsibilities seriously, and does his job well.
Unfortunately, after he loses money after a badly thought-out investment in a new media company (the company violated another person's patent rights, and the third company waited until a larger company with deeper pockets bought it to sue for infringement), Logan regresses and acts irresponsibly once more by taking a trip to Vegas with the Life and Death Brigade colleagues, Colin and Finn. He finally tells his father that he won't be part of the family business anymore, and starts to straighten out again.
After he gets an offer for a new job in California, Logan proposes to Rory. She considers, but turns him down, feeling she wants to accomplish other things first. She asks if they can continue their relationship in a long distance form but Logan decides that it would be too hard for him to continue seeing Rory after the proposal and after moving, he gives her an ultimatum, all or nothing. Rory decides that she can't do that so the heartbroken Logan breaks it off with her.