In a crowded residential suburb on the outskirts of Tokyo, four teenage girls indifferently wade their way through a hot, smoggy summer and endless 'cram school' sessions meant to ensure entry into good colleges. There's Toshi, the dependable one; Terauchi, the great student; Yuzan, the sad one, grieving over the death of her mother - and trying to hide her sexual orientation from her friends; and Kirarin, the sweet one, whose late nights and reckless behavior remain a secret from those around her. When Toshi's next-door neighbor is found brutally murdered, the girls suspect the killer is the neighbor's son, a high school boy they nickname Worm. But when he flees, taking Toshi's bike and cell phone with him, the four girls get caught up in a tempest of dangers - dangers they never could have even imagined - that rises from within them as well as from the world around them.