Hidechiyo's journey through the Sengoku Era begins when they befriend Tōkichirō, an ambitious merchant seeking out Amrita, and Mumyo (無明, Mumyō), a demon hunter of the Sohaya group, eventually playing a critical role in the rise and fall of the warlord Toyotomi Hideyoshi.

Kashin Koji serves as the main antagonist, a mysterious entity linked to a powerful yōkai known as Otakemaru, who obstructs Hidechiyo's progress at every turn and is responsible for manipulating many of the events that take place through the game.

Returning historical characters from the first game includes Tokugawa Ieyasu, Tadakatsu Honda, Saika Magoichi and Oda's African retainer Yasuke.

Other historical figures such as the Heian period onmyōji Abe no Seimei, tea master Sen no Rikyū, Katō Danzō and Okuni also appear to aid Hide in their adventures.

Nioh 2 received three downloadable contents following its release, each DLC taking place post-game where Hide is sent back in time to the Heian period to solve the mystery of the Sohayamaru's origins and Otakemaru's hatred towards humanity.

The second DLC, "Darkness in the Capital", has Hide allying with Abe no Seimei, legendary demon slayer Minamoto no Yorimitsu and her Shitennō against Ashiya Dōman's plots.

The game begins with the Shiftling protagonist, Hide, being awoken from a recurring nightmare and after saving a villager, finds a mysterious letter leading them to Jusanzakura.

The two befriend each other and enter the employ of Saitō Dōsan, also meeting the demon hunter, Mumyō along the way, but shortly after, Dosan's successor, Saito Yoshiatsu, rebels.

Kashin Koji leaves Toshimitsu's body, who realizes what has happened and urges Hide to protect Mitsuhide as he is killed by Tokichiro and his forces.

Realizing that Kashin Koji was responsible and has corrupted Tokichiro, Hide is forced to flee alongside Mumyo and Mitsuhide to ally with Tokugawa Ieyasu.

After meeting with Mitsuhide's new persona, Tenkai, and the tea master, Sen no Rikyu, Hide heads to the battlefield of Komaki and Nagakute to confront Tokichiro, killing him.

Hide and Mumyo learn that Sohayamaru can be restored by combining the former's dagger with the latter's sword guard talisman and a large quantity of Spirit Stones.

Returning to their senses, Hide reunites with Mumyo and allies with William to stop Maria from resurrecting Tokichiro, believing he will continue to fan the flames of war.

Catching Maria off-guard, Koji tries to possess Tokichiro but Hide stops him, forcing him to fight them in a spiritual battle as he transforms into Otakemaru.

As William captures Maria and returns to his son and Hattori Hanzo, Hide and Mumyo bid farewell to Tokichiro as his spirit moves on to the afterlife before the two set off to hunt down hostile yōkai that still threaten the land.

Continuing Yoshitsune's mission, Hide encounters the Guardian Spirit, Oh, who leads them to an ancient shrine containing a small box, which upon opened, pours out light which resonates with Sohayamaru.

When Yorimitsu is called upon by her retainer, Sakata no Kintoki, to head to Rashomon Gate, Hide follows them as they encounter and are captured by the spider Yokai, Tsuchigumo.

Resuming the pursuit, Hide defeats Doman first in his human form, then once more when the evil onmyōji sacrifices his body to summon the Lightning God of Yomi.

With the newly created Sohayamaru in their possession, Hide heads to Onigajo to confront Otakemaru, who transforms his Guardian Spirit into an Aratama, fusing with it to become the Nightmare Bringer.

Its stellar combat is elevated by the addition of Soul Cores, Burst Counters, and the ways in which those two main new mechanics affect enemy AI and how you approach battles.

"[17] While GameSpot stated, "Ultimately, that excruciating difficulty and the feeling it evokes are baked into Nioh's DNA, though, and its boss fights remain compelling even as they vex and frustrate.