The Battle of Nagashino, 1575

The Takeda calvarly were among the most feared in the nation, and had not yet come up against the kind of volley-firing technique employed by Nobunaga's men. They would have charged in full of confidence, only to see the front-line utterly decimated by the timed volleys of the arquebus ashigaru.

The arquebus had been in Japan for awhile by this time, but the warlords were still experimenting with it's usage. This marked the first time that the volley-firing technique had been used in such a large-scale battle between two of the biggest names in the land.

You also have to remember that most of the casualties in battles like this were not generally suffered in the battle itself, but during the retreat, and this was most probably the case at Nagashino as well. After the Takeda's initial charge was stopped dead, the army would have retreated with Nobunaga's forces in pursuit, and this would have resulted in a great number of the losses for the Takeda.

What I find even more interesting than the battle itself and the great deal of Takeda men slaughtered is that somehow the Takeda limped on for another 7 years... truly amazing considering their losses in this one engagement.

Again had it been for Takeda Shingen the battle may have looked differently as he would never lead such a foolish rush. There is still a debate about samurai not charging in the battle on horses because the horses of that age were too small for the purpose. Yet naginata and nagamaki are supposedly used for cutting off horses legs among others and strangely enough there are weapons with the likes gekken, yagara-mogara and different types of yari's that are apparently anti-cavalry. My point is the prime weapon of a mounted samurai would probably be the bow, may be there were yari armed samurai as well, but facing an enemy that has fortified so well (not to mention it's their chosen position on the battlefield given that positioning was among the most valued strategies along with speed) it was foolish to charge an army that outnumbers you - supplied these circumstances it's doubtful that musket armed soldiers (around 3000 of them) brought much of a difference as it was not a fully developed tactics at this time.

Sadly enough it was Takeda Shingen's indirect fault that his clan was completely wiped out as his clansmen were old Oda's enemies and Shingen himself was among the best daymio during that age who specialized in taking the enemy by surprize with an army of the likes of 12,000 men more or less.

I asked this same question on another Japanese history forum, because I also struggled to see how effective a samurai charge could be due to both the size of the horse and the fact that most of the time the mounted troops were mixed in with their foot-soldier attendants, rather than being placed in mounted-only squads. But that is how they were used, as mobile shock troops. If you look at artwork from the 16th Century you can see mounted samurai charging in to the attack surrounded by other mounted troops and foot soldier attendants.

Most of the fighting by this time was being done by the ashigaru footsoldiers anyway, with the mounted troops probably being used to "mop up" and chase down the fleeing army.

The bow was traditionally the weapon of the samurai, but this had become essentially phased out by the time of Nagashino. The use of mass armies, from around the time of the Onin war forward, instead of individual combat between the two combatants had seen the importance of the bow diminish.