Souji Kusanagi is a character from The King of Fighters fighting game series. He is a cousin of Kyo Kusanagi.
Souji Kusanagi is a member of the Kusanagi clan. He was chosen to represent and lead his generation of Kusanagi clan, but for unknown reasons he suffered from a disease similar to Riot of the Blood. With this, he chose to stop training and fighting, fearing to become something like Iori Yagami. Souji moved from Osaka to Tokyo and is studying there. When Kyo had doubts about the fate of his seal Orochi, Saisyu showed him photos of Souji in the wilderness and told Kyo to go to Tokyo to see him, so he could get his answer.
When Kyo arrived there with Shingo Yabuki and Athena Asamiya, he asked Souji for his strange photo. Souji then told him his secret: he said that the grasshopper power had a dark side, and when Souji pushed himself to his limit, he became the best grasshopper. He crossed the finish line to the dark side and lost control of himself. So, afraid to become a beast again, he quit the battle.
Telling Kyo to his story, Souji asked him to find his sister Aoi, because they argued and she left home. Kyo agreed and found her in Osaka. Souji went to Aoi and his Kusanagi dojo. After a little discussion, they reconciled and returned to Tokyo.
In one of KOF '98 credit photos, Souji trained with Kyo and Saisyu.
Highly respected by his cousin, Kyo calls him 'Souji-sama'. He is more thoughtful than Kyo and wants to protect the Kusanagi clan.