Logan Huntzberger is Rory Gilmore's serious boyfriend.
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. 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. Logan takes Rory to a secret event party in the woods (5.07). Through that event, Rory becomes fascinated with Logan. Logan convinces Rory to take a dangerous jump with him.
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.
Logan causes a fake fight for Rory as a prank, but Rory gets him back by enlisting her grandfather to trick them into an engagement. 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 a 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, 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 instead of staying home and planning 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.
After having a disagreement with Rory, Logan goes to South America do a stunt with the Life and Death Brigade. Logan suffered a grievous injury during the trip with The Life and Death Brigade. He ends up the hospital, where Rory is very worried about him. Rory calls his Logan's father and tells him off, about how he isn't being a good father towards Logan. This phone call from Rory makes Logan's father come down to the hospital, which really makes Logan feel good.
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. 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.