|This article is about a/an character in Kamen Rider Build.|
Prime Minister Himuro met with the other prime ministers for their monthly report meeting via a hologram. She gave an update on Hokuto's latest projects of child care and agriculture programs and their success to Prime Minister Himuro of Touto. She then proceeded to ridicule Prime Minister Mido's efforts in Seito as selfish and ridiculous and seemingly was amused by the fact that the Skywall prevented the country of Japan from reunifying. When Prime Minister Himuro tried to extend his hands to shake hers and Mido's to agree on the next meeting, both left and terminated the communication.
She later berates Prime Minister Himuro for being unable to deal with the Kamen Rider and Ryuga Banjo and letting them escape into her capital. She believes that this was done intentionally by Himuro or Mido to cause widespread panic among Hokuto's citizens and that the Kamen Rider is a secret weapon of war. Her accusations are stopped as Prime Minister Himuro's son Gentoku calls her out on her seemingly hidden intent to attack Touto by causing hostility, saying they will deal with her problem and abruptly terminates her holo-transmission.
After the proxy fight between Build and Grease, Tajimi attempts to back out of her agreement with Touto by ordering her army to attack Touto immediately, but is stopped by Blood Stalk. When Tajimi angrily questions what he is doing and reminds him that the course of action had been his idea, a squad of Seito's Guardians storms her residence. Stark reveals that it had been his idea to send the Hokuto army for a surprise attack so that Seito could take the whole of Hokuto with minimal resistance. Prime Minister Masakuni Mido of Seito orders Tajimi be taken into custody. As the Guardians restrain her, Seito's Kamen Rider, Kamen Rider Rogue, enters the room dragging a destroyed Hokuto Guardian. Behind her disappearance which is unknown to Sawatari, Tajimi is actually abuducted by Evolto as he experiments her by fusing with Nebula Gas. As Sawatari escapes from Utsumi who abducted him, Tajimi shows up much to his shock as she transforms into Owl Lost Smash by using Fukurou Fullbottle to battle Grease until Sento intervenes to save him. However Sawatari warned him that behind Owl Lost Smash is actually Tajimi and she would be killed if Build would defeat her before MadRogue interferes to battle Build and Grease. Tajimi's Nebula Gas is later neutralized after her Lost Smash form was defeated by Build Genius Form and she forgives Sawatari for her mistakes before Evolto suddenly appears to retrieve the Fukurou Fullbottle from Sento. Sento orders Sawatari to escort Tajimi to safety.
In the new world, she is a member of Prime Minister Himuro's new cabinet and serves as Japan's Minister of Welfare.
Due to the exposure of Nebula Gas, Yoshiko was power hungry, manipulative, and willing to endanger the lives of her subordinates to acquire the Pandora Box. After the Nebula Gas was neutralized, her true personality was revealed as she displayed great remorse for her actions and asked for Kazumi's forgiveness.
Behind the Scenes
Yoshiko is portrayed by Ryoko Gi (魏 涼子 Gi Ryōko).
- She is only Prime Minister that is currently alive.