Man, this was beautiful. I can't help but think that all of you folks who are confused by it just haven't had the experience of loving someone who feels like they don't deserve love or happiness for whatever reasons they may have.
Miyu cooked dinner for Kaede. Kaede loved it. Miyu had flashbacks to something in her past where she cooked for someone who hated it and rejected it and she had to feed it to the dog instead. Presumably someone she had strong feelings for since it left such a deep memory. It made Miyu feel loved.
And then Kaede told her she loved her, and they had sex. And Miyu is conflicted. Pages 13 and 14 are all about how Miyu feels worthless and unlovable. She doesn't believe it when Kaede says that she loves her. She doesn't think she deserves it, so obviously Kaede couldn't possibly mean it.
I'm a little unclear on when, exactly, Kaede gets drunk, but it's after that, and after Miyu talks to the other girl in the bar. And then Miyu goes over to Kaede's house some indefinite time later after Kaede has sobered up.
Which brings us to the present day.
Personally, I loved the story. My current partner is very much someone who feels broken and undeserving of love and happiness because she was molested and abused as a child, and we are constantly rubbing up against those issues. Whenever things are going too well between us and she starts to get too happy, something in her psyche kicks in and starts trying to push me away. So the story certainly resonates with me.