Successfully complete the game on the Normal difficulty setting to unlock the "Movie Viewer" and "Sound Test" options under the "Extras" menu.
After winning the battle on the beach against the minor Boss that resembles a giant crab and you can move onward to the next area, save the game, but do not proceed ahead. Instead, backtrack to the beach and defeat the enemies modified with the Mashogane. They will not stop respawning, and will provide an unlimited amount of Mashogane to boost your weapons attacks to their maximum at this point. Kill off a good number of them, then when a large number of enemies are present, use your Kamui to take them out. This may also give you a healing item such as a Miracle Pill or Tengu Herb. Note: Retreat back to the save point whenever your health gets low. Do not use your healing items as you will need them for the Boss fight that is just past the save point near the Soul Gate.
When there are many enemies that are grouped together, use Shizuka and equip Fleck. Then, run toward the enemies. Press Triangle while running. Try to hit an enemy with more health than the others. This attack deals damage but also plants a bomb on the enemy. Hit the enemy with any other attack to detonate the bomb. The explosion of the bomb does not hurt you.
When fighting a Juggernaut, use Benkei. Equip Benkei's club and hold Triangle until his club glows and sparks. Then, release Triangle and charge into the Juggernaut. Be careful not to press R1 before holding Triangle.
While in Kamui mode, press Circle if the "Circle" symbol appears instead of any other attack. This deals more damage. If the "Circle" symbol does not appear, then choose another button (for example, Triangle) and press Circle afterwards. This deals more damage.
When you get knocked down, press X to get up. If timed correctly, just as you hit the ground, you will jump back up. If you do not time it correctly, press all buttons a few times to get up more quickly.
To perform longer jumps, use Shizuka and equip Fleck. Run in any direction and jump. Just before you start falling back down, press Square and the direction you wish to travel. This attack will make Shizuka float forward in the air for a brief moment.