This one isn't as good as the others, sadly.
Koyomi is established as a resourceful girl who isn't too shy to ask for help. And although she seems reserved she certainly isn't gloomy like the author of this story seems to suggest.
So this is wildly out of character.
Still, it's great to have a story about Koyomi, there are so many great characters that don't get enough exploration in the official story. But it would have been even better if this had been a story that used the understated versatility of the character more.