Neither in Bleach, nor here, did the childhood friends win. In Bleach, Orihime was a classmate that Ichigo knew through his actual childhood friend, Tatsuki. Other than Aizen trolling her at one point her only relevance was bringing Orihime into the plot. I supported Ichigo/Orihime but he knew Rukia probably just as long.
Here, Yotsuba isn't the childhood friend, they only spent a day together. She's "First Girl all along" (which is different from First Girl, that is Itsuki). Chapter 100 makes it clear childhood friend is Takebayashi.