This thread is full of people downplaying whats in the game by using phrases like "a few gay characters" and "just one transgender character" and "only one quest about it." They've either not played the game or theyre trying to make a point and attack people by dishonestly representing the content in the game.
There are 6 characters (including the player character) at the 'home base.' Each of these characters is non-hetero and includes 3 gay males, 1 transgender MtF, an asexual female, and a bisexual female (who ends up dating the transgender character). There are 0 straight characters here.
Their sexuality doesn't play a role in the story whatsoever (include even being mentioned) until you do the side quests, which can be skipped if you don't want the achievement. Each of the five other characters have a chain of quests that start off mostly involving farming enemy drops and finding specific chests in the campaign. The quests fill in the back story and motivations of each individual character. As you get to the end of each character's quest chain, you start learning about their sexuality. When you complete all five characters' quest chains, you're given a fairly lengthy cut scene (it might be the longest cutscene in the game aside from the ending), where the characters site around a campfire talking about their sexuality and past relationships and so on. After that, another scene plays where the player character begins a relationship with the transgender character.
yikes. almost seems the main story was added in at the last minute ---