Before Kuroko can begin to look into the explosion that rocks Marimo Academy, the culprit turns herself in, which raises questions about whether this girl really is the bomber or is something more sinister going on behind the scenes.
Now under Kuroko's care, Rinko has just transferred to Hinako's school, and things are already off to a bad start! A sudden explosion rocks the school, and Kuroko is called in to catch the one responsible for the attack. But before she can get started, the culprit turns herself in voluntarily! Is this girl really the bomber, or is there something even more sinister behind the scenes...?
