The Chunichi Dragons announced on January 4 that they signed an official partner contract with Mizuno. The Dragons will begin wearing Mizuno uniforms this season. Designs for their uniform will not change.
Source: Nikkan Sports 1/4/2018
[UPDATE 1/5 @ 9:37pm]
The agreement runs from January 1, 2018 until December 31, 2021. Mizuno joins Edion (helmet) and Chunichi Shimbun (uniform, left sleeve) as official partners.
Source: Chunichi 1/5/2018