I feel like the author wanted to see how Tomo and Misuzu (from Tomo-chan) would be like in a lesbian relationship but can't really do it because the entire story of that manga is centered around Tomo's romance with a her male childhood friend and the author doesn't want to pull a Joou-sama no Esshi. So the author made this one-shot as a means to see how Tomo-chan would be like if it was a yuri manga without having to actually make Tomo and Misuzu gay. How else would you explain how the girls in this one-shot look like Tomo and Misuzu with different colored hair, because the author never showed this level of laziness when it came to character designs in Tomo-chan.