To unlock Shigurui difficulty, beat the game on Shura difficulty. In Shigurui difficulty, you will only have 1 HP.

After completing the second endings with both Kisuke and Momohime, the white barriers on the map will disappear. You will be able to face the Bosses from both characters' Story mode again. Defeat the following Bosses to unlock the corresponding accessories:

ACCESSORY - HOW TO UNLOCK
A Pair Of Clappers - Defeat Musashi (Momohime's storyline).
Cloisonne Rosary - Defeat Yamato (Kisuke's storyline).
Dragon God Belt - Defeat Mino (Kisuke's storyline).
Dragon God Gauntlet - Defeat Suruga (Momohime's storyline).
Dragon God Mask - Defeat Yamashiro (Momohime's storyline).
Imari Platter - Defeat Iga (Kisuke's storyline).
Iwami Poison - Defeat Shinano (Kisuke's storyline).
Izumo Charm - Defeat Hida (Momohime's storyline).
Jade Matagama - Defeat Mino (Momohime's storyline).
Merchant's Abacus - Defeat Totomi (Kisuke's storyline).
Ninja Socks Version 2 - Defeat Yamashiro (Kisuke's storyline).
Nio Bracelet - Defeat Suruga (Kisuke's storyline).
Sacred Tree Tablet - Defeat Ise (Momohime's storyline).
Shura Seal - Defeat Sagami (Momohime's storyline).

Unlock the following alternate endings by performing the corresponding tasks:

ENDING - HOW TO UNLOCK
Kisuke's first story ending - Defeat Tokugawa Tsunayoshi.
Kisuke's second story ending - Beat both characters' story. Equip Mumei Tamanoo and Tsukiotoshi before you enter Tokugawa Tsunayoshi's Boss arch in Edo Castle.
Kisuke's third story ending - Beat both characters' second story. Equip Oboro Muramasa before you enter Tokugawa Tsunayoshi's Boss arch in Edo Castle, then win the battle.
Momohime's first story ending - Defeat Fudo-Myoo.
Momohime's second story ending - Beat both characters' story. Equip Mumei Tamanoo and Tsukiotoshi before you enter Fudo-Myoou's Boss arch in Yamato, then win the battle.
Momohime's third story ending - Beat both characters' second story. Equip Oboro Muramasa before you enter Fudo-Myoou's Boss arch in Yamato.

To regenerate a randomly placed soul, save and quit the game. Then load the game back up.

If you are relying on the main-screen's "expanded map" (not the map from the sub-screen), you can scroll the map left and right without moving Momohime or Kisuke. To do this, have them kneel down, then pressleft and right (on the diagonals) to get your bearings.

Complete Story mode for both Momohime and Kisuke to unlock an option to view the credits at the title screen.