If you only watched the Doukyuusei anime movie (which covers Volume 1), you have only seen the prologue. Volume 2 ( Sotsugyousei ) is the heart of the story.
Have you read Doukyuusei Volume 2? Does it live up to the first volume for you? Let us know in the comments below. doukyuusei manga volume 2 full
Many readers searching for get confused by the sequel titles. If you only watched the Doukyuusei anime movie