Warning: This post will be boring to most people. Read only if you are looking for a mobile phone provider in Japan or if you're trying to decide if the Softbank White plan is right for you.
If you're in Japan and haven't heard about Softbank Mobile's new White Plan, you've been living under a rock. For 980 yen a month, they offer free SMS and MMS messaging to other Softbank users and free voice calls to other Softbank users between 1 AM and 9 PM. Calls to other companies' phones and calls to Softbank phones between 9 PM and 1 AM are 21 yen per 30 seconds. To send and receive MMS messages (anything more than short text messages) a monthly fee of 315 yen is required. For people who either don't make a lot of calls or usually call other Softbank users the monthly bill could be under 1500 yen per month.
I'm that kind of user so a week ago I applied to switch to the White Plan. As a matter of background, I got new phones for my wife and myself last month on the "New Superb Bonus Plan" which means (as Softbank representatives usually present it) that in exchange for a two-year contract, Softbank subsidizes the cost of a new phone. I found that this isn't exactly the case. In reality, the discount doesn't apply to the cost of the phone; it applies to the basic monthly fee, optional services, and calling charges. What this meant to me was that if I switched to the White Plan which comes to 1300 yen per month with the optional services I need, I would lose most of the discount I thought I had.
What I had on my side was that the Softbank representative who had sold me the phones had explained the discount incorrectly and had actually written the wrong information on my contract. Even with that, it took four days of arguing with the telephone customer service, the assistant shop manager, and finally the shop manager before I got any kind of resolution. First there was a lot of "sorry we didn't explain things fully enough" and "we explained it in an easy-to-understand way rather than confuse you with details" but when I kept pointing out that their explanation to me was just plain wrong and that they even wrote it that way on my contract, the store manager finally relented. She gave us Tomomi's phone for free with no strings attached and let me downgrade my phone to a model that would lower my monthly bill by about 1000 yen. Even though it's an older model, I actually like it better. It's bulkier, but it has more features and I fat-finger the keys less frequently.
There's a reason that most of AU's advertisements focus on customer satisfaction. With the transition from Vodafone to Softbank and with ever-changing price plans, even the Softbank employees don't know the details of their company's offerings. Shop carefully and get everything in writing.