Well, here is the family tree
http://images4.wikia.nocookie.net/powerinstinct/images/8/84/Goketsuji_Family_Tree.jpg

SHINJURU GOKETSUJI:Yagyu Jubei's illegitimate Child. As his father he was a great swordsman. Initiator of the Gouketsuji lineage.
OKIKU: Sasaki Kojiro’s cousin.
CHOSHICHIRO GOKETSUJI: He married 4 times but divorced of all of his wives. He had children with each of his ex-wives and for that reason he and his children lived as a low class family. He trained his children and grandchildren to be hired as Kurokos.
SAHACHI: Apparently dead at birth. Once in the tomb, Sashichi; the tombkeeper, saw him breathing. He decided not telling to the family and adopted him as his son, naming him Sahachi.
SHINTARO GOKETSUJI: Went to America by boat
SHINOSUKE GOKETSUJI: He arrived to the wild west and joined to the cavalry. During the moving of the frontier, he had a cultural exchange with the Amiyai tribe. He liked their way of living and stayed with them. Later, he got married with an Amiyai girl
THOMAS CREIGHTON: He adopted the surname “Belti”.
KAJURO GOKETSUJI: Joined to a Iga ninja clan to learn Ninjutsu. He adopted the surname of that clan once he was approved. The surname is Hattori.
SAKURAKO HATTORI: She was saved from a wild dog that was chasing her in the mountains by Kokuin Kanji, Kanji became friend and training partner of Gennai Hattori
SUZUNOSUKE KOKUIN: He started to work in a palanquin shop to visit one place after another and swindling foreigners. Later, he established a photo studio. He died in a trip.
SUZUNO SUSUMU KOKUIN: After the death of his father, he traveled to many places. He married in his journey.
KANJI KOKUIN: Oshima obligated him to marry with Oume. During their marriage he adopted the surname "Goketsuji" due to the rules of the clan. Kanji and Oume get divorced two weeks after their wedding.
SADAKICHI GOKETSUJI: He had the No. 1 Ornamental Hairpin Shop in Yoshiwara. His work was carried to an International exposition in Paris. His work was liked by the courtesan of an Arabian King and was hired as designer. Once in arabia, he was introduced to Sahad Asran Nadia, known as the Queen of the Dance. Later He got married with her
KYUSAKU GOKETSUJI: By request of his father, he gets in charge of the family shop. He went to Russia to purchasing new products for the shop. There, he met a Japanese man named Kino Yabungo, who had shop in Russia. After the Russian Revolution, Yabungo went to Bankruptcy and Kyusaku helped him to return to Japan. In gratitude for his help, Yabungo offered him his daughter in matrimony.
FUTABA KINO: She was a widow before get marry with Kyusaku. Motoki is the son of her former husband.
DARREL: Adopted. He was the son of Tatta’s sister in law.
SAEMON GOKETSUJI: He ran Away from home due to a conflict with his family. He went in a fishing boat from Yokohama to Osaka then to Shikoku, Nagasaki and Kyushu. Finally opened a print shop in Dejima (was the beginning of the souvenir shops) got married in Nagasaki and adopted the surname "Suzuki".
HEIJI GOKETSUJI: He adopted the surname “Goketsuji”
JOHNNY WAYNE: Opened a gym at the age of 35. His wife Elizabeth abandoned him when Keith was 2 years old.
SAYLA CREIGHTON: She worked for an Aristocratic Russian Family. Felt in love at first sight with a work partner and get married with him. They founded a bank in United Kingdom.
LIZA HAMILTON: Her husband adopted the surname Hamilton.
Retrieved from "http://powerinstinct.wikia.com/wiki/Family_Tree"

that was the only thing missing from the game