Escorted by Grays, Blackthorne enters Osaka Castle for Lady Ochiba’s birthday reception. He bows correctly, parries Ishido’s insult by asserting his samurai status, and receives a public pledge of protection after the recent night attack. Blackthorne’s gallant camellia gift wins Ochiba’s approval, and his dictionary fascinates the court as Ishido and Ochiba discuss training their own interpreters.

Christian Regent Kiyama challenges Ishido about trade, and Blackthorne endures Kiyama’s contempt for his sect. Mariko introduces her son Saruji. Then Mariko declares she will leave Osaka at once to meet Toranaga with Kiritsubo and Lady Sazuko. In a tense exchange, she forces Ishido to state she is not formally confined, but he threatens a Regents’ ruling. The confrontation is cut short when Ochiba is summoned to the dying Lady Yodoko; Ishido follows.

Back at Mariko’s quarters, Yabu scolds her for provoking Ishido; Mariko and Blackthorne quietly agree to speak later. Kiyama arrives with Saruji, pressing Mariko to apologize and remain until a ruling, warning of consequences for Saruji’s betrothal. Mariko refuses, affirming her paramount duty to Toranaga over requests from Regents or Ochiba.

Kiyama probes Blackthorne’s threat to the Church. Mariko praises Blackthorne’s seamanship, recounts his contests with Rodrigues, and explains Toranaga likely freed and armed him to use against Portuguese power and Kyushu’s Christian daimyos. Kiyama decries her “heresy,” but listens as she argues Ishido may also see Blackthorne as a weapon.

Pressed for secret intelligence, Mariko reveals a reported plot by Onoshi to kill Kiyama, information sourced via Uraga. She then delivers Toranaga’s sealed message: Ishido has allegedly promised the Kwanto to Zataki after Toranaga’s death, betraying Kiyama’s interests. Kiyama is visibly affected yet denies trusting Toranaga, concluding Mariko herself may be the sacrifice that proves Toranaga’s sincerity.