I forgot to mention about the adapters. Japan uses almost the same plug as the US, except they don't have a ground (third prong). There's a good chance your chargers don't use ground either. If that's the case, no adapter needed. If you happen to have something that has a ground, you can get grounding adapter for pretty cheap at a grocery or hardware store.

Japan uses 100V, 50 Hz (east) / 60 Hz (west). Most electronics operate ok in that range, but do check the labels. It doesn't look like you considered it, but don't bother bringing a hair dryer. It likely won't work properly.