This is one of the three Crows Gaiden volumes done by Takahashi Hiroshi himself. It says Crows in the title, but really, it's more closely related to Worst than Crows. It focuses on Tesshou's and Guriko's year, so it's set the year after Crows (main series) has ended. There are only one or two minor Crows spoilers in there, so you can read it without ruining your enjoyment of Crows. It's also an ideal entry point for those who want to read Worst without having to wait for the Crows scans to finish.