A price war between major smartphone carriers is escalating, with SoftBank Corp. unveiling new plans Tuesday that put it toe-to-toe with rival NTT Docomo Inc. and the firm's planned price cut.

Responding to the bombshell announcement by NTT Docomo earlier this month stating that it plans to launch a ¥2,980 a month 20GB plan from March, SoftBank said it will also introduce a 20GB data monthly plan for the same price.

“Competition in our industry is very tough, so moves by our competitors are one of the factors that drove us to decide (on the price cut),” SoftBank Chief Operating Officer Jun Shimba said during a news conference.