Kanbei is a Yellow Comet CO who pays more money to make his units overwhelmingly powerful.
Day-to-day Effects: All of Kanbei's units have 30% increased offense and defense, but cost 20% more to deploy.
Power: Morale Boost -- All of Kanbei's units gain 20% increased offense and 10% increased defense.
Super: Samurai Spirit -- All of Kanbei's gain 20% increased offense and 30% increased defense. Kanbei's units also have an additional 50% increased offense when counterattacking.
Kanbei has a very rough early game, and often must grab the closest properties possible just to not get behind in vehicle count.
You may have to build a lot more infantry, and a lot fewer tanks, but never fret, as Kanbei's units are, pound-for-pound, the best ones in the game. Units of most COs will actually take more damage than they deal in same-unit matchups, even when they get first strike.
Most opponents, realizing that, will try to fight with more expensive units like MD tanks. Artillery will easily deal with them, and it is possible to clean them up afterwards with light tanks.
Always try to save up for Samurai Spirit; your day-to-day bonuses will do the job most of the time, and Morale Boost is rather weak for 4 stars.
Kanbei may have serious difficulties on maps where he has to build transports; he gains nothing much from transport units, and building them will take a large cut out of the funds Kanbei desperately needs early on. Think twice before picking Kanbei on such maps.