Hi,
I have some knowledge (i learn it since some decades) in Japanese history and i must disagree.
Cavalry charges were used in Japanese battles, the most famous is at Nagashino in 1575 were Takeda Katsuyori was discomfited by Oda nobunaga.
Takeda opened the attack with the old-style order of battle: four waves of mounted warriors charged one after the other against the defences erected by Nobunaga . They were all destroyed before they reached his front line. Nobunaga had set up wooden palisades in a zig-zag pattern, of a height which horses could not overleap. Takeda's cavaliers were brought up short against this obstacle and were shot down from behind it by some 3,000 foot soldiers armed with muskets. Every successive charge of the Takeda warriors was repulsed with heavy losses, while the defenders suffered hardly a scratch. (Sir George Sansom, A History of Japan 1334-1615, p. 287.)
I would say that cavalry charge was the speciality of Takeda Shingen. He vanquished at the battle of Mikata ga Hara (1572) on account of it. Takeda army was nicknamed kiba gundan (騎馬è»å›£
(mounted army).