According to Ryoichi Sugimura from NTT DoCoMo , DoCoMo will release a Tizen smartphone in Japan in Q3 or Q4 of 2013. At the same time in Japan technical testing of a device code named Samurai by Samsung has been completed which is due to be released by DoCoMo. There is also another device with the code number SGH-No55. Both devices are tri-land LTE (2100 (B1) / 1500 (B21) / 800 (B19) MHz) and dual-band W-CDMA (2100 (I) / 800 (VI / XIX)). NTT DoCoMo have stated that they have worked with Samsung to design and build a high-end device.
Source Tizen Hub