Takanashi Naiki served as a bushō from the Sengoku to early Edo periods.  His actual name is uncertain – Naiki is the title of an official of the Ministry of Central Affairs.

According to accounts from the late Edo period, Naiki was either the son or grandson of Takanashi Masayori and Masayori’s daughter (or younger sister) married Sanada Nobutsuna, and, on that basis, served the Sanada family, but the authenticity of this account is questionable.

Naiki had a deep relationship with Sanada Nobushige.  Nobushige served as an instructor and kept one of Naiki’s daughters as a consort.  His son’s maid-in-waiting was a foster sibling.

Naiki made contributions at the First Battle of Ueda.  After the Battle of Sekigahara, Naiki accompanied Nobushige and Sanada Masayuki, moving to Kudoyama.  After the demise of Masayuki, although most of the retainers departed from Kudoyama and returned to their former territory of Ueda, Naiki and his son remained in Kudoyama and supported Nobushige’s entry into Ōsaka Castle.  In the end, Naiki, along with Nobushige, appear to have been killed in action at the Summer Campaign in the Siege of Ōsaka.

During a ransacking that occurred after the fall of Ōsaka Castle, Nobushige’s third daughter (Naiki’s grandchild) named Oume was protected by Katakura Shigenaga and became his second wife.  However, Oume’s mother may have been the daughter of Ōtani Yoshitsugu and Nobushige’s formal wife named Chikurin-in.  In this case, there would be no blood relationship between Naiki and Oume.