Rei

Rei
	; Rei as he appears in the manga.
Name in Kanji	レイ
Name in Romaji	Rei
Alternate spelling(s)	Ray, Lei
Fighting Style	Nanto Suichō Ken
Allegiance(s)	Kenshirō
Family	Airi (younger sister)
Position(s)	Mercenary
Appearances	Manga (ch. 26-82), Anime (ep. 23-57), Rei Gaiden
Voice actor(s)	Kaneto Shiozawa; Shin-ichiro Miki (Shin Kyūseishu Densetsu); Takehito Koyasu (Hokuto Musou)

Rei (レイ) is the successor of Nanto Suichō Ken (南斗水鳥拳, "South Dipper Waterfowl Fist") style and is one of the Nanto Rokusei Ken, bearing the destiny of the "Star of Justice" (義星, Gisei).

When the Man with Seven Scars (Jagi) killed his parents and kidnapped his sister Airi, Rei abandoned his humanity and roamed the wastelands as a lone wolf, surviving through any means necessary. Rei was hired by the Fang Clan to infiltrate Mamiya's village as one of its bodyguards. However, Rei betrayed them and helped Kenshiro thwart them off, believing it would be wiser to side with the stronger side. Afterwards, Rei went to the hideout of the Fangs with Ken and Mamiya to defeat their leader. However, the Fangs had managed to capture Airi from her previous captors and used her as leverage to coerce Rei into fighting Ken for them. However, Rei and Ken managed to trick the Fang Clan by striking each other's vital points at the same time, placing both of them in a temporary false state of death. After the Fang Clan was defeated, Rei was reunited with Airi.

Rei would become one of Kenshiro's most trusted allies. He exposed Amiba's true identity at the Village of Miracles and accompanied Kenshiro to the city of Cassandra, where the real Toki was imprisoned. Although Toki was saved, Rei was forced to rush back to Mamiya's village when he learned that Ken-Oh's army began to mobilize his troops. Rei fought the leader of the invasion squad and then challenged Raoh himself to a fight. However, Rei was defeated and struck in the vital point Shinketsushū sentencing him to three agonizing days to live.

After rescuing Mamiya from Medicine City, Rei learned that she was once one of Yuda's captives before she escaped and became the leader of her village. Swearing to avenge Mamiya's honor, Rei dedicated his remaining days to tracking down Yuda. However, Yuda managed to elude his pursuit, leaving Rei's struggle in vain. This was until Toki extended Rei's lifespan for another day by striking the vital point Shinreidai, which had the side-effect of transforming his hair white. Rei entered the final showdown with Yuda, and after a treacherous fight, he defeated Yuda with the technique Hishō Hakurei, the Soaring White Splendor. After the battle, Rei tells Kenshiro to live on as the hope of the new world before spending his final night alone in a hut to spare his friends and family from his gruesome death. Afterwards, Kenshiro ignites the hut as a funeral pyre for his fallen friend.