Passing by each other / Ships passing in the night / Missed connection

I thought we would always be together—my childhood friend's fiancé. But he chose someone else instead. However, the girl who stepped aside because she wanted him to be happy hears from the girlfriend he had chosen that the two of them have broken up. What?! If the two of them broke up, then what was the point of me stepping aside? This is the story (main part) of a girl who tries to reconcile the childhood friend and his girlfriend for the sake of her beloved childhood friend. The main part wrapped up quickly, and now we've moved into the side stories. Originally, it was supposed to be a brief conclusion, but it seems many people enjoyed it, so the side stories have continued to the point where the main part has become the bonus. Because of this, I feel like I've committed synopsis fraud, but please bear with me.