Oh my goodness. Nothing could have prepared me for how laughably bad that ending was. I wasn't expecting much, but at the same time I wasn't expecting THAT. The conclusion contradicted what we had spent nearly 30 chapters learning (that Maki likes boys). We saw neither the development of Maki's feelings for Youko nor the aftermath of her and Youko getting together. The last chapter was just a completely isolated point in time that coincidentally resolved all open conflicts at once. Essentially the author is telling us "And then Maki totally realized her feelings for Youko. The End."
Ironically, the last chapter would have been better off (read: mediocre) as a one-shot. Instead, grafting it onto this series like a second head creates the Platonic ideal of how not to end a story.
Just wow.
