Shizu Wakisaka (脇坂 静, Wakisaka Shizu), better known by her first name alone, is a secondary character in the Samurai Shodown series. She is the lover of Haohmaru and is affectionately called, "O-Shizu" (おしず), alternatively spelled "Oshizu", by him. In return, she addresses him as "Haohmaru-sama". He left her behind so that she wouldn't be faced with the dangers of his journey. Though left alone, she has faith in Haohmaru and prays for his safety. She is 16 years old in Samurai Shodown. Her overall character is similar to Otsū from Eiji Yoshikawa's novel Musashi.
She is voiced by Kikue Nishiyama.
- In Samurai Shodown, during Haohmaru's ending, she will appear to him, having followed him to Shimabara. He dismisses her, telling her that he can't choose between his sword and his woman and leaves.
- In Samurai Shodown II, she will run to the wounded Haohmaru's side. She will plead with Genjuro to not kill him, which spared his life. He will then apologize to her, as he still wants to dedicate himself to his swordplay.
- In Samurai Shodown IV, Haohmaru will shout out her name if he's defeated.
- In Samurai Shodown 64, When you fight on Haohmaru's stage, she is seen walking away as part of stage's intro. Haohmaru will also mention her name during battle.
- In Shinsetsu Samurai Spirits: Bushidou Retsuden, a special cutscene will occur if Haohmaru is the main hero in the second chapter. They will meet by coincidence in Kyoto, both being surprised at seeing the other. They spend the rest of the day together, Shizu pouring Haohmaru his sake in a red sakazuki (large serving cup). He promises to someday tell her his tales about the world, leaving her on a happier note than other meetings.
- In Samurai Shodown VI, during Haohmaru's ending, he repeats his words to her from the second game and leaves her. In Rasetsumaru's ending, when his demon half announces his plans to replace him, Haohmaru protectively demands that he leaves Shizu alone.
- In the third title of Days of Memories, she will sometimes appear to ask the protagonist about Haohmaru's whereabouts.