Written by Kōki Mitani, it stars Masato Sakai as the samurai Sanada Nobushige.

Pro-Tokugawa daimyōs Production Credits NHK chose to cast Masato Sakai for the lead role of Sanada Nobushige, a samurai of the Sengoku period.

Minoru Kubota of the Yomiuri Shimbun assumes that this is in part to increase viewership for the historical series after years of declining audience numbers for taiga dramas, as Sakai was a popular actor in the dramas he previously starred in.

[3][4] Due to the decline in viewers of NHK's taiga dramas, which is especially seen in the historically low ratings of preceding taiga drama Hana Moyu in 2015, the public broadcaster strengthened its effort to market Sanada Maru in order for viewership to increase.

[4] Lead actor Sakai was sent out by NHK to major media outlets for interviews, though he was found to be uncooperative in many of them, as questions would focus on his personal life instead of his new role in the drama.