I didn't quite understand what Yamashita meant on the last page by "Cause that self of mine from back then finally got to meet Takahashi, just maybe". Can anyone enlighten me?
(Lemme try...)
Yamashita was taken back to that old self of hers (emotionally), finding herself in a somewhat similar situation. However, this time Takahashi was there.
Figuratively speaking, the present day Yamashita was standing next to that child and saying "guess we are the same huh"/"Oh, so I'm still you...", but Takahashi joined the picture, showing both of these versions of Yamashita a different way of looking at stuff. So, to her, it's like this old-self got to meet Takahashi briefly.
At the panel here https://dynasty-scans.com/chapters/still_not_normal_today_ch09#8
It's like Yamashita was in that mental space alone where only her and her old self stood — with her memories manifesting themselves as the child. And Takahashi entered this space and greeted both of them. "I used to be alone, stuck in that place, but now Takahashi is here to change this (emotional) place"