Chapter 1: Way of the Ninja
This stage is very straightforward, meant to introduce you to the basics of Ninja Gaiden's gameplay elements. Your goal is to reach the ninja fortress's Inner Sanctum, where Murai waits for you. Along the way, you'll find messages detailing the skills you'll need to use in order to proceed past that particular point. Remember them well, as you will most certainly be using them again later on.
There are still a few secrets to be found, however. At the very beginning of the stage, there is the corpse of a fallen ninja. Examine it to receive an Elixir of Spiritual Life. You'll want to do this whenever you encounter the bodies of those less fortunate than you, as they often carry valuable items. From there, instead of going up the hillside path, go directly backwards from where you started. There's another chest here with another restorative in it. Now, proceed up the hill, making use of the techniques described along the way, to reach the fort. Don't worry if you miss these, though - you'll have an opportunity to collect them again at the beginning of the next stage.
There is a fairly simple puzzle in this stage you'll need to complete before you can fight the boss. The door to the inner sanctum is locked at first, however, you probably remember seeing the Samurai statue earlier in the stage holding a conspicuous object. This is the key you need, but you'll need to get another item first. The large, enemy-infested room right before the path to the inner sanctum has a trap door in it. (You may have even fallen in here by mistake.) This leads to the Underground Storehouse. Besides lots of bats (which are easy kills and yield lots of essence and life refills - remember this!), the storehouse has a few items for you to make use of. One of these that doesn't seem to have an immediate use is the Fangs of the Samurai. But if you remember, that statue was missing something. Hmm! You'll need to backtrack a bit to reach the statue, but fortunately, the path out of the Storehouse takes you to an earlier point in the stage. Examine the samurai statue and you'll automatically use the Fangs, getting the key to the Sanctum in return. Head back towards the Sanctum, save your game at the Dragon Statue and then head towards your very first boss faceoff.
Chapter 1 Boss: Murai
Are you ready for your first real challenge? Murai is a master with the nunchaku and he'll strike at you hard and fast. He also has a slower, charging attack that can completely break your guard and leave you wide open to further attacks if you don't dodge away from him quickly. But again, Murai is basically training for fighting bosses and other enemies with strong defenses. The key here is to try to strike Murai during one of the few times when he's open to attack. There are different ways to accomplish this, but we suggest either launching directly into an attack after you finish guarding a combo of his (this is a fairly safe move, but he's more likely to block you), or rolling around to his sides or back as he's about to complete an attack (you're more likely to catch him when he's open, but you're left quite vulnerable, as well). If you wind up in a weapons clash, with your Dragon sword and his nunchaku locked against each other, mash the square or triangle buttons repeatedly to try and overpower Murai. If you're successful, you'll have another great attack opportunity as he recovers.
If you're having trouble, there's an Elixir of Spiritual Life hidden in a pot in the back of the room that can be picked up and used for healing. Try not to lose all your life, since the Talisman you got in this level is the only one you'll be getting for quite some time and you'll want to save it for a far more difficult encounter. If you feel you've used up too many of your healing supplies, don't be afraid to reset and try again from the last save point - practice and knowledge are truly the keys to doing well against Ninja Gaiden's bosses. (This applies for any and all tough enemies in this game, as well.)
The battle ends automatically when Murai gets down to about 25% of his life. After a brief cinematic scene, you'll begin chapter 2.