Everyone has one now it is my turn...

FAMILY

Yuzu, Obasama [Grandmother/Deceased]: An old lady who had raised Ren when he was small, she tried to keep him from following the path of the shinobi. However his talent and abilities would not allow him to escape this fate, as she was once known as the White Death she took it upon herself to protect him from the clutches of his father, and the control of his clan until she died. However she made an unknown agreement with the Mizukage in order to prevent the clan from using Ren to mass produce the clan's kekkei genkai. How she died is still unknown, but what is known is that she loved him very much. She died when he was around six to seven.

Yuzu, Genpachi [Father/KIA]: A harsh cold hearted man who saw his son only as a tool to help him take over the village of Kirigakure. He was known as the Black Death, but was never able to defeat his own mother who had managed to stop him everytime. However things change and while it is believed that he died in a covert Konoha assassination, his name has been stirred up in the Yuzu Clan Village with rumors of an alliance with the Osada Clan

Yuzu, Kin [Mother/Mysteriously deceased]: She was much like Ren's father only happy to have given birth to a child who possessed their clan's greatest ability. She was presumed to have died in child birth, but there are other more pressing secrets hidden deeply within. She had also been exiled from the clan for attempting to use one of the clan's forbidden techniques.

Kuroka, Gin [Adoptive Mother]: Ren was discarded by his clan for unknown reasons and was then put up for adoption as there was no longer any place for him to stay. Being a stubborn boy he would bite, hit or fight the whole process never understanding it to begin with. When he met Gin things changed since he thought the village finally decided he was a threat and had to be taken out by a shinobi in bandages. After some trial and error, with a little bit of patience and an awesome display of her sword. He took a liking to her mainly for her sword, but later he grew closer to her calling her mommy. Making her the first person to gain his trust deeply enough for him to call her by that. He calls his mother Shinobu when asked about his mom on missions, as he knows some of her secrets. Ren will not allow anyone to speak badly of or hurt his own mother

Flynt, Sanosuke [Guardian/MaybeDad]: He first met this man in a bar, but ignored him. He then met the man again in an epic fight against his first sensei and future rival Kenji Chikara. He was impressed changing his opinion of the man, when finally he met the man for the third time through his mother who called him Sanoteme, which is the name he used for Sano to this day. It is unclear whether he will ever be corrected and he also trained under Sano in the arts of Senjutsu...

Kuroka, Chie [Sister]: Unknown

Kuroka, Reiko [Sister]: Unknown

Kuroka, Shinji [Brother]: Unknown

Kuroka, Misao [Daughter]: Unknown

Rivals & Senseis
In the end once you learn all they can teach you, it becomes the students job to teach the teacher

Kenji, Chikara [Bukijutsu Sensei]: Kenji had done a mission with him, and being impressed both ways they had a spar. The rumors of the spar did spread but not so well known like some epic battles in the past. He learnt how to use strange weapons and fight against them, while also learning of Kenji's skills in other areas like genjutsu as well. He felt that he won that day as Kenji had fled, while in truth Kenji may have just felt tired of sparring for the day

Uzumaki, Mitsuhide [Fuuinjutsu Sensei]: The strongest shinobi he had ever met outside of his village, he held a deep respect for the power of the former Hokage who had gone missing recently. In heading to Konoha in search of his former sensei he encountered another man, who would later change his fate.

Senju, Sousetsu [Rival]: Whether it was destiny or fate, there is something about this man that makes Ren want to fight, to compete, to defeat him and show he is the strongest there is

Friends

Orochi, Risu [Friend]: They met in the hot springs of Konoha which after a nice day shopping in the market place and eating they eventually had a sleep over which would be a night he would never forget.

Kamikira [Assumed KIA]: A woman who had attempted to adopt the young Ren to her cause, her sudden disappearance in the Seven Bells war led to the massacre of many pirates who did nothing to deserve such brutal deaths other than the fact that they were involved in smuggling. He looked up to her greatly and is still saddened by her disappearance.

Underlings or Students
I carried you under me so you an underling, if you want to change that become strong

Oomi : One of the most stubborn, troublesome and worst genin's he had to look after besides Taiga. He had many issues with her as he had to look after her during missions as she seems to feel nothing, not even the fear of dying at any moment

Taiga : There are no words to describe the gray hairs this boy gave to Ren. In the end the boy at least showed promise before seeming to go missing in action.

Dovy : The most respectful student or genin he had ever had, they were meant to go on a mission to stop the Blue Turban Rebellion but Dovy ended up being AWOL putting this important mission on hold indefinitely as authorities search for signs of what happened to the young shinobi.

Uzumaki, Toshiko : A young cocky boy who wants to fight him for some reason, the boy was trespassing and should be killed. However he overlooked it and would teach that boy something that day