Minae Noji, who voices Karai's mother Tang Shen in this episode, had previously played Karai herself in Teenage Mutant Ninja Turtles (2014).
Leonardo says yokai will steal peoples' souls through their butt. This is an existing Japanese legend known as the "shirikodama" ("small anus ball"), which the yokai remove from people's bodies to kill them.
Hamato Yoshi and Oroku Saki were designed after martial artist Shin'ichi Chiba. However to make them distinct, but Yoshi has bigger pupils and bushier eyebrows than Saki.
Tang Shen is mentioned as having Chinese ancestry. This explanation helps explain how the Japanese character Shen is able to have the Chinese name Tang, something that was never explained before in the TMNT saga.
This episode reunites Yuri Lowanthal, Ashley Johnson and Greg Cipes who have voiced previously voiced Ben Tennyson, Gwen Tennyson and Kevin Levin the three main characters from Ben 10: Alien Force and Ben 10: Ultimate Alien.