Step1
If playing on the Samurai Warriors:Xtreme Legends expansion, import data from the original Samurai Warriors if you haven't done so already. SKIP THIS STEP if you are not playing Xtreme Legends.
For help on importing data, see:
http://www.ehow.com/how_2108980_samurai-warriors-samurai-warriorsxtreme-legends.html
Step2
Set the difficulty to "Hard" or "Chaos", or if you are playing on Samurai Warriors:Xtreme Legends and have purchased the special bonus available from the options menu that allows you to obtain 5th weapons on Normal difficulty, you may set it to Normal instead.
http://www.ehow.com/how_2108979_set-difficulty-samurai-warriors.html
Step3
Begin Free Mode or Story Mode and play as a created officer wielding a spear. Play the Siege of Osaka - Summer stage on "A New Hero's Tale", and be sure to choose the stage on the upper branch.
Step4
No special items will be useful for this stage, so equip whatever items suit your taste. Begin the stage; you'll start inside Osaka Castle near the Sanada-Maru, the main gate to the south.
Step5
Exit the castle through the main gate and head for the two officers that will be indicated by blue dots once the first mission starts. You'll have to lure them to the blue X.
To do this, approach one and get him to follow you (hit him if necessary), then approach the other and get him to follow you as well. Once they are both chasing after you, lead them forward toward the castle until Yukimura says "Begin the attack!"
Step6
Defeat the two officers you just lured forward (Tadanao Matsudaira and Toshitsune Maeda). By the time you've done this, you should have gotten the mission to destroy the Tokugawa cannons. Head for the cannons in the east first.
Step7
Disable the cannons by either hitting the cannons enough to destroy them, or by knocking their riders off their stands. Once you are done, move towards the other two cannons (indicated by blue dots) and disable them in the same manner.
Step8
Your next mission will be to assist Yukimura as he tries to reach your ommander Hideyori Toyotomi. All you have to do to clear this mission is make sure no Tokugawa generals breach the castle; simply defeat as many enemy generals as you can before Yukimura reaches his target.
Step9
Begin by heading southeast and defeating Tadaoki Hosokawa and sealing the nearby stronghold. Then circle westward and defeat Kagekatsu Uesugi and seal that stronghold as well. Keep moving and eliminate Takatora Todo, Masanobu Honda, and Tadamasa Honda as well, taking the time to seal any strongholds along the way.
Step10
Continue north and defeat Tadateru Matsudaira. This will mean that all Tokugawa generals in the field have been cleaned out,a nd only Ieyasu Tokugawa and Hanzo Hattori are left. If Yukimura has not reached Hideyori yet, go to the northwest of the map and hang out near Osaka's west gate.
Step11
Once Yukimura reaches Hideyori, after some dialogue, Masamune Date will arrive in the northwest to reinforce the Tokugawa army. Defeat him before he can enter the castle, as directed by the mission.
Step12
After Masamune has been eliminated, re-seal any strongholds in the area you may have lost. After this is done, move towards the front entrance to the Tokugawa camp; you'll have to get there by way of the small bridge in the south.
Step13
Eventually after some dialogue, Hideyori Toyotomi will retreat inside the castle, and Yukimura will charge the Tokugawa camp. Cross that bridge into the fortress before he does and wait for him.
Step14
Once Yukimura reaches the fortress, the north gate will close, trapping you inside. Take note of the number of kills you have; to complete the next mission, you will have to defeat 100 enemies inside the fortress and approach Yukimura.
Step15
After a brief cutscene, a supply team will appear in the northwest. THIS IS NOT THE RIGHT SUPPLY TEAM, so if you're just after the weapon, ignore it. However, chasing after it won't jeopardize your mission to assist Yukimura, so you want to get the rare item "Warrior's Tale", you can take the time to go after it.
Step16
Continue fighting your way toward Ieyasu until you reach his main camp. Once you're inside, a supply team will appear outside the Tokugawa camp in the west, heading east. Go back outside to hunt them down and grab the weapon from the camp.
Step17
Charge into the Tokugawa camp again and finish Ieyasu off to complete the stage. The Tombo-Giri is now yours!