The Chi-Nu II was one of two planned improvements to the Type 3 Chi-Nu. The primary goal was to up-arm the Chi-Nu with a Type 5 (75 mm) found on the Type 4 Chi-To and Type 5 Chi-Ri. The first plan was to simply mount a Chi-To turret on top of the Chi-Nu hull, which was tested at the Japanese firing range at Irago, with tests found satisfactory. The second plan was to fit the Type 5 cannon inside of a regular Chi-Nu turret, which is represented by this version.

It was introduced with the initial Japanese Ground Forces tree in Update 1.65 "Way of the Samurai", but was released once all the rank III Japanese tanks were available to the public in the Closed Beta Test. The Chi-Nu II is a combination between two vehicles, the Type 3 Chi-Nu and the Type 4 Chi-To. It has the armour of the former, but the gun of the latter. Thus, while presenting itself as a more vulnerable body with only around 50 mm of armour, it has slightly better mobility than the Chi-To, a smaller profile, yet carries the same gun. Like the Chi-To, the Chi-Nu II should be played in a sniper-like format from a distance rather than up-close to the enemy and fighting them in close-quarters.