Marluxia and Larxene know each other through being members of Organization XIII. Being numbers XI and XII respectively, it is likely that they were recruited at around the same time. Marluxia and Larxene were eventually sent on a mission to Castle Oblivion. He had a plan to overthrow the organization that Larxene was in on. In fact, she was the only one who was really loyal to him. They both worked together on manipulating Naminé and Sora as well as deciding what to do with Vexen when they realized that he was not loyal to them. Larxene was eventually killed by Sora and the same later happened to Marluxia.
MarLar is a decently popular pairing and one of the most popular het ships regarding members of Organization XIII. A lot of fans base it on the fact that they worked together in Castle Oblivion and the fact that Larxene was the only one who was really loyal to Marluxia. Some even speculate that there might have been something between them. Since both turned on the organization, many feel that they would not go with anybody else but each other.
- While many of the organization members woke up as their whole selves again, it is unknown what happened to Marluxia or Larxene.