Once upon a time, on another site, I and another player joined a Kingdom Hearts RP as two novice Keyblade wielders. Per the main plot of the RP, each of our characters ended up in Traverse Town following a Heartless attack in each of their respective worlds. The other player’s character (Muse A) had a bit more experience with the Keyblades and whatnot than my character (Muse B), who knew next to nothing and was still worried sick about the state of his own world.
The first sign of potential chemistry between Muses A and B came about when the GM’s character (Muse C) started going into a whole infodump of the main plot, including a big spiel involving Sora, Riku, Xehanort, etc. Muse B had absolutely no idea what he was talking about and nearly walked out on the group altogether, but Muse A realized how Muse B was feeling and convinced him to stay. The thought of romance still hadn’t occurred to me yet, but the way Muse A was able to understand Muse B’s feelings (without actually knowing the full details of his situation) and then calm him down when no one else could definitely hinted at the beginnings of a possible connection between them.
Then the first fight scene began. Muse A, who was primarily a mage, fought more from a distance, while Muse B, a swordsman who didn’t stand a chance in a head-on confrontation with the enemy at the time, focused instead on protecting the group’s two mages (Muse A and another mage character) and providing support for them, including taking out the nearby lights to hide them from the enemy. Eventually the group had to fall back, so Muse B again helped the mages to reach the inn where they had all been told to take shelter. As Muse A was thanking Muse B for the help, she said the line that first led me to see the potential for a much deeper connection between the characters:
“Oh, and thank you for protecting me. You’re the very warrior I thought you were and I'm glad I'll be able to work with.”
This compliment was unexpected on my end, but it resonated really well with Muse B. At the time, Muse B had recently shaken off a toxic ends-justify-the-means mentality that had led him to do some very morally questionable things, so for Muse A to openly state that she had always seen Muse B as a good person from the very beginning was a really positive influence on him and on his self-esteem.
The RP itself eventually died out for external reasons beyond our control, but Muse A’s player and I liked the chemistry between Muses A and B so much that we eventually branched out into 1x1 co-ops featuring the two and in subsequent remakes of the original RP, including talks of possible shipping scenarios. Among the most notable of these was a remake of a “beta test” I had done with a new player to help them with their plans for a new future Keyblade wielder (Muse D). In the original beta test (in which Muse A was not present), Muse D had brutally murdered several guards and priests in a temple while trying to free her father from imprisonment there, and that among other things led Muse B (who was already royally pissed off at Muse D for mistreating Riku earlier) to come dangerously close to giving in to darkness altogether just to stop Muse D. All of this would’ve spelled certain doom for the group dynamic and the main plot, so I called in Muse A’s player to help us retry the beta under practically identical conditions (even copy-pasting most of my and Muse D’s posts from the original beta) and see if Muse A’s presence could provide the balance needed to avert the disastrous breakdown of the original beta. Sure enough, Muse A successfully managed to prevent Muse B from going completely off the rails, whether by directly calming him down during their confrontation of Muse D, by discreetly turning his focus away from the aftermath of the mass murder, or simply by being there to give Muse B a more positive outlet for his emotions (Muse A was horrified to the point of tears, and Muse B stopping to comfort her was a big help in snapping him out of his blind rage mode at the time).