thishas probably be answered but IDC I LOVE LGBT TRIO! this'll be a lot to read soooo....
ocho and keji are the closest of the three, being childhood friends years ago before their separation, ocho is the reason keji is able to learn what a heart beat sounds like. keji will do just about anything for ocho with no regard of how others feel (except ocho and mona maybe) and ocho is literally on a journey to search for keji while having to regain parts of her memory.
dae is newer to their dynamic so it takes some getting used to in the dynamics shift, dae and ocho are somewhat forced to learn to understand each other since they end up being demon hunters together but they bond from overcoming traumas together and sharing parts of their backstories to one another, building trust
dae and keji are a whole other story since when keji first meets him they just Hate him. they know he's becoming close to ocho and get jealous and paranoid abt their relationship with ocho, it takes a lot of reassurance and their own alone mission with dae for keji to overcome it and for dae to realize he likes both ocho and keji at some point BLEEEEHHHH