The Ki-21-Ic, designated as the Type 97 Heavy Bomber (九七式重爆撃機), was the third variant of the Ki-21 production series. Following the improvements from the Ki-21-Ib to the control surfaces, it also came with more machine guns and larger fuel tanks increasing its range.

The Ki-21-I hei was introduced during Update 1.65 "Way of the Samurai" as a reward vehicle for the 2016 "Winter Holiday" event. It was later made available as a battle trophy vehicle in the Warbond shop from the Battle Pass: Season I, 75th Anniversary of the Great Victory until the end of the Battle Pass: Season IV, "Fearless Voltigeur". While on the surface, the Ki-21-Ic looks like another Ki-21 with a name change, the amount of machine guns was tripled, with two MGs added on each side of the plane and a remote-controlled gun directly in the tail which will destroy any plane directly on the six of the Ki-21.