Commenting about the lack of plot, I think it's because if we see the time table from the game, the whole episode 1 was still the first day, which on the game is is still the prologue/introduction of the characters.
But yeah, it's also fail to do right introduction of, at least, the main characters except maybe for Maeda and Haruka. Heck, Aki and Rina don't even properly interact with Maeda
