SoftBank recently acquired U.S. carrier underdog Sprint for $21.6 billion and CEO Masayoshi Son looks like he’ll be a ferocious competitor to the U.S.’s top carriers, particularly during the FCC’s upcoming spectrum auctions.

When the Japanese government recently awarded unused 2.5 GHz spectrum licenses to SoftBank rival carrier KDDI, Son lectured government officials for 50 straight minutes. Son argued that the process was unfair to SoftBank’s users and that he was “prepared to die” in order to get this message across, according to the Japanese Daily Press.

The Japanese government awarded the spectrum to KDDI citing that it had better utilization plans for deploying the frequency indoors and in tunnels.

SoftBank is requesting the records regarding the government’s decision be made public and Son is threatening to file suit if the Japanese government does not disclose its reasons for the move.

Son’s aggressive behavior has surfaced before. The Japanese Times said that Son had previously threatened to set himself on fire inside a Japanese government office unless state-owned carrier NTT DoCoMo hurried up its work on network infrastructure that SoftBank user’s need for connectivity.

As the FCC prepares a number of spectrum blocks for auction as early as 2014, U.S. carriers are getting in position for bidding. Sprint in particular has its eyes on 10 MHz of 1900 PCS H Block spectrum the FCC could put on the block in January. Dish Network already holds licenses adjacent to the spectrum going up for grabs so it could emerge as a rival bidder to Sprint.

Sprint has also come out in support of competition-enhancing measures taken by the FCC in proposed incentive auctions for 600 MHz spectrum.

In both cases, Son’s fiery temper could come into play and could make rival bidders think twice about going up against Sprint for spectrum.