Fuuma Arashi appears only in the Naruto anime. He was the hope of the Fūma clan's shinobi who tried to rebuild their clan and Sasame's cousin. He and some others joined Orochimaru to gain the power to rebuild the Fūma clan. Source: http://naruto.wikia.com/wiki/Arashi
Yakumo was the heir of the Kurama clan. A savant in Genjutsu she was the pride of her clan. When her parents were killed in a fire, she was turned over to Yuuhi Kurenai to watch over. Sandaime felt Yakumo's talents were wild and could bring about disaster for Konoha. Kurenai later felt she could not properly train the young woman, so her powers were sealed away and she was sent to a mountain retreat for her own protection.
Raiga is a member of the Seven Swordsmen of the Mist along with Zabuza and Kisame. He appears only during a filler arc. He uses pikes as lightning rods (lightning is an energy source for him) and can put them together to make an even more powerful 2 bladed weapon. He travels along with a small disabled child named Ranmaru, whom is the only person he cares for.
Sylphiel is a priestess of the shrine to Flare Dragon Ceifeed in Sairaag. When she was young, she took the Bless Blade from the shrine and hid it under the holy tree, Flagoon. This later proved to be useful, as the sword was needed to defeat Copy Rezo-Zanaffar. After each destruction of Sairaag, Sylphiel was involved in the efforts to rebuild it. Her life revolves around helping other people. Sylphiel is an extremely gifted cleric of white magic. She's more powerful in the art than other white magic-using characters like Amelia Wil Tesla Saillune and Naga the Serpent. Unfortunately, her skills in other areas of magic are lacking. She has not mastered the basic fundamentals of offensive magic like shamanistic or black magic spells. The most famous example is her version of Flare Arrow, which looks more like a small carrot than an actual Flare Arrow. Sylphiel is openly attracted to Gourry, and this makes Lina uncomfortable. (Source: Kanzaka Wikia)
Erina Pendleton first appears as a small girl, with Jonathan rescuing her from bullies. When she appeared again, she and Jonathan was going out, and eventually they fell in love. However, after Dio seized her, kissed her, and then brutally beat her, she felt humiliated and stayed away from Jonathan for a long time. She did not appear again until after Dio's first near-defeat, when she nursed Jonathan back to health. After that, Jonathan finally defeated Dio using the Ripple. They subsequently renewed their relationship and got married. They took a ship to go on their honeymoon to America, but the voyage was cut short by the appearance of Dio. The ship went down, and Jonathan stayed behind, trying to kill Dio. Erina took an orphaned infant and escaped. Years later, she and her grandson Joseph Joestar were the last of the Joestar clan, and they traveled to New York on the invitation of Speedwagon, which sets off the events of the second story arc. (Source: Wikipedia)
Alone (Ar�n) is a young painter and also Hades' previous incarnation. He is an Italian orphan raised alongside Sasha and Tenma, who later become arch-enemies. He is the purest soul on earth and believes that everybody has a good side and disapproves the use of violence, which is why Hades chose to reincarnate in his body. At first he rejects his fate as the God of the Underworld, but is convinced later by Hypnos, and sealed by Pandora's kiss. Before Tenma leaves for the Sanctuary, they make a promise that, while Tenma tries to become a Saint of Athena, Alone too must try to become a good artist so that he can finish the painting of Tenma when they once again reunite. During the next two years, his personality makes a drastic change after seeing everything he painted dies. Convinced by Hypnos, he starts to believe that death is the ultimate salvation. And to bring salvation to the entire world, Alone starts to paint the Lost Canvas, a painting of the Earth viewed from space, so that after he finishes it, the entire world will die. It has been implied that Alone is not yet totally possessed by Hades as Alone drew in the Lost Canvas an image of Tenma, Sasha and himself in their childhood. After seeing this, Pandora uses a seal given by Hypnos and Thanatos to seal him in a dimensional isolation, in hope that he will continue painting the Lost Canvas without distractions, and to keep him away from the reaches of anyone from his childhood life.
Akahoshi took over leadership of Hidden Star Village after the previous leader, the Third Hoshikage, suddenly grew ill and died.