Ryūzetsu

was an ANBU-level kunoichi from Kusagakure, who appears in Naruto 5: Blood Prison.

Background
Ryūzetsu belonged to the Grass Fruit Group of Kusagakure, and was childhood friends with Mui's son, Muku, and they all dreamed of resurrecting Kusagakure. Eventually, she witnessed Mui sacrificing Muku in a failed attempt to open the Box of Ultimate Bliss, leaving only his green scarf that she would wear as a bandanna for the years to come, and Ryūzetsu became very grief-stricken. She eventually allowed herself to be arrested and placed into prison Hōzukijō, where Mui was the master of, in order to stop Mui from opening the Box of Ultimate Bliss again, as well as avenge Muku.

Personality
Ryūzetsu was mildly serious as she was not amused by many things, such as Naruto's antics. She was also very strong willed and quick witted. She has shown to have some form of feelings for her childhood friend, Muku, as shown when she did whatever she could to stop him when he went on a rampage. She was not scared at putting her life on the line or dying for friends, as seen when she not only jumped in front of Naruto, and was impaled by Muku, but as she also gave her own life to save Naruto's, because she could not have lived from the injury that she had sustained.

Appearance
Ryūzetsu had long white hair that flows to her waist that is covered by a green bandana which belonged to Muku and blue eyes with multiple circular patters much like Kurenai Yūhi. She wore a sleeveless kimono over a green top that only has a long green sleeve covering her left arm along with the green bandana. Both her arms were bandaged up to her elbows. She also wore black trousers with shinobi sandals. Overall, she disguised herself as a man in order to infiltrate Hōzukijō, and nobody knew of her gender until she took off her kimono to dry off in front of Naruto.

Abilities
Ryūzetsu was considered a genius by Muku, and she was an ANBU of her village. She can use Fire Release: Demon Lantern to create fire-like apparitions to attack her opponents, even with the Fire Release: Heavenly Prison reducing her access to her chakra. She can also use her clan's kekkei genkai, which allows her to heal or restore life in exchange for her own.

Plot Overview
Ryūzetsu first met Naruto in Hōzukijō as a fellow prisoner, warning him not to get himself into more trouble than he already is in. Later, when Naruto attempted his second escape by jumping off the cliff and into the raging ocean, Ryūzetsu followed him and warned him not to, to which he ignored and did anyways. She jumped after him to save him, revealing to Naruto that she's a woman. Telling the young ninja of her mission, they formed an alliance to take down Mui and the Box of Ultimate Bliss.

She later attempted to assassinate Mui while he was sleeping, but it was Maroi in disguise; this encounter allowed them to form another alliance. During a prison riot Maroi started, Ryūzetsu took advantage to attack Mui, but it turns out to be Kazan in disguise, by which time the real Mui brought the Box to the prison yard, with Naruto's chakra to open it. Ryūzetsu was surprised to hear that Mui's wish was to see his son once again, instead of reviving Kusagakure, and was horrified when Muku, who came back out of the box, became corrupted by Satori and impaled his father.

Throughout Satori's rampage, Ryūzetsu kept trying to reason with Muku, with Satori's ability of sensing fear and killing intent being ineffective against her, due to her lack of either. Eventually, when Satori thrust his claw at Naruto, Ryūzetsu jumped forward to block it, only for both of them to be impaled. Naruto eventually defeated Satori and Muku with the Wind Release: Rasenshuriken with Mui's help, and Muku and Mui died together. Ryūzetsu remembered her old times with Muku, and shed tears for his death. When Naruto's stab wound was too much for Sakura to heal, Ryūzetsu stepped forward with her Dragon Life Reincarnation to save Naruto's life at the cost of her own. She and Mui were then buried outside Hōzukijō, with Muku's bandanna tied around her gravestone.

Trivia

 * Her name means "dragon tongue".
 * Ryūzetsu has Rinnegan-like eyes, except they are lighter with a smaller ripple effect.