Less than one hour ago, Softbank Mobile‘s charistmatic CEO, Masayoshi Son, just completed an unexpected (予想外) press conference at the New Ohtani. Just as stippy.com reported last week, Mobile Number Portability (MNP) is starting this week in Japan and promises to upset the comfortable duopoly of DoCoMo and Au.

Stippy.com recevied a lot of email from readers suggesting that MNP would be a non-event, but it appears as though that is not the case. Son-san wants to join these two giants in the big technological sand pit they call success.

Following on from his amusing 予想外 TV commercial series featured last week, Son-san has made an even more unexpected announcement today. Anyone who signs up for Softbank’s new “Gold Plan” will be entitled to a Yosogaiwari (予想外割):

Free email,

Free SMS,

Free voice to other Softbank subscribers…

and as an extra teaser the first two months are completely free (including the monthly fee).

Good-bye to hard to understand teigaku (fixed price) plans, the only thing that you will have to pay for are calls to non-Softbank subscribers and access to internet sites. Better yet, the entire package will only cost you 2,880 yen per month. Given that the average person spends about 7,000 yen per month on their phone bill, that could save you about 50,000 yen a year. (Multiply that by a family of four!!)

So, you say (As I would expect any cynical reader of stippy.com to ask), what is the fine print? Son mentioned in the press conference that this deal is only available until January 15, 2007. Interestingly, Son claims that everyone who signs up between now and Jan 15 is entitled to the 2,880 yen / month plan for ever (this guy is serious).

Clearly the other “catches” have to do with what is not free. Son didn’t go into details about the pricing of calls to other carriers or the packet charge rate for accessing the internet, but absent of a large hidden price rise, this should be cheap too (Softbank is well known to be the cheapest carrier in Japan). Furthermore, Son made it very clear that it is his intention to win both the battle and the war. If either DoCoMo or Au announce reactory price cuts, he’s promised to respond with a similar package – only 200 yen per month cheaper – within 24 hours.

The only potential “catch” that we could think of was to do with area coverage/bandwidth. After Willcom introduced unlimited free calls and email between Willcom users, their network suffered serious capacity issues and had to rapidly speed up their infrastructure expansion plans. No doubt Softbank will suffer the same problem. Son has promised to double Softbank’s area coverage (number of base stations) by next March which should help stem some of the increased usage, but who knows if he will complete it in time?

Eyes and ears are now focused on Au and DoCoMo to see how they will react to such a move. Son made it very clear in his presentation tonight that he had no intention of letting DoCoMo and Au continue to earn their monopoly profits. (Remember these companies made a total of 15 billion US dollars of profit between them last year!!) And so, may the games begin!