Worst case scenario, Ichika’s IS doesn’t respond for some reason (be it zero shield energy or some other technical problem) and Ichika plummets into the ocean and breaks every bone in his body, or worse, he gets expelled from the school for jumping from cliffs. Really, how does an IS fit inside of a bracelet? Maybe they use teleportation technology to pull their IS’s out of alternate dimensions. Any way you look at it, it doesn’t seem to be a very good idea to go jumping off of cliffs assuming that your IS will pop up. As soon as we see an instance in the anime of someone’s IS not responding, my point will have been proven.