In Chronicle Mode, the player can unlock and play as the games NPC's. There are five unique female NPCs that can be unlocked who have lip-syncing, unlike other NPCs:

Tazu Iio - Naotora's retainer and best friend. She also makes an appearance in Chronicle Mode
Hana - Saburo/Kagetora's wife.
Otsū Ono - Nobuyuki's Concubine.
Tsuru - A famous warrior shrine maiden.
Teru Kushihashi - Kanbei's wife.

In the Oda campaign, there is a cutscene where Nō remarks that Hanbei is the modern Zhuge Liang, which is a reference to the character from the Dynasty Warriors series.

Takakage Kobayakawa makes an appearance in Samurai Warriors 2: Empires during a pre-battle event. In the event, he responds to his Motonari's words of encouragement along with his brothers Motoharu and Takamoto.

Nobuyuki made his first appearance as a character in Samurai Warriors 2: Empires in one of Ina's special event (resulting in their marriage), before getting a more prevalent role in the third main title.

Munenori Yagyū, Koshōshō and Hisahide Matsunaga had appeared in previous games as bodyguards.
• Munenori in Samurai Warriors
• Koshōshō and Hisahide in Samurai Warriors 2

According to producer Hisashi Koinuma, Naotora's design is based off of Japanese actress Satomi Ishihara.

In previous titles, Nō's designs were based on a butterfly motif and the use of beautiful clothing. For the fourth game she was made to match Nobunaga's demon-like armor. However, due to the number of ideas coming in for Nobunaga's design, the finalized version of Nō's design had to wait until his were approved

Although all returning characters were redesigned for the game, Musashi and Kojirō's designs and models are the same from Samurai Warriors 2.

According to an illustrator, Hayaken, so many people from the company had different ideas for Nobunaga's new design, that it resulted in many arduous compromises. They tentatively made his outfit as unique as possible and something not seen before in the series.

Nobuyuki was originally going to be designed with the same hair color as Yukimura. The hair color was constantly changed until the developers settled with silver hair.

Gracia's illustrator, Katsuki Onda, pushed for the idea of her having long hair. He was unable convince his artistic supervisor until he presented her current design with pigtails. The goal was to make her as "cute as possible" with quasi Gothic Lolita appeal.