Yoshiko Tsushima

"'Cunning As The Snake, AquaBlack!'""-roll call""'With The Slyness Of The Snake, Super AquaBlack!'""-second roll call"Yoshiko Tsushima (津島善子) is AquaBlack of the Aqours Rangers.

Personality
Self-asserted and mostly-delusional, Yoshiko believes that she is a fallen-angel cursed by God with bad luck. While cool-headed at times, she is sometimes a boneheaded and gets easily-tempered. Despite being an anti-hero, she is very kind and caring, values her friends more than anything. She mostly acts as the group's tsukkomi (straight man), but mainly with Hanamaru and Ruby.

Background
Not much is known of Yoshiko's past except she and Hanamaru were childhood friends and even went to same kindergarten and two develop feelings for each other. It was then Yoshiko found a black feather and believed that she is Yohane The Fallen Angel. This lead her to be outcasted by classmates over the years, except for Hanamaru.

In Episode 4, Yoshiko witnessed the five-man team Aqours Rangers defeat Demon Doubter. She then comments that a fallen angels job is to aid the demons. In Episode 5, Yoshiko secretly helps Demon Angel to fight the Aqours Rangers but gets tricked by him and almost gets herself killed until the Aqours Rangers save her. Hanamaru convinced her that people will accept her whether she is Yoshiko or Yohane and that fallen angels can redeem themselves to help those in need. Because of that, Yoshiko joins the Aqours Rangers as AquaBlack and then summons Aqours Snake to form the Doubutsu Gattai Naga-Oh.

In Episode 18, ever since the Demon Angel incident, Yoshiko hasn't been acting like herself. It turns out Demon Angel placed a mark on her, causing her to separate herself from her doppelganger, Yohane. It gets complicated when her teammates hurt Yohane, they are hurting Yoshiko as well. After being told to separate herself from Yohane by aiming for the crystal heart, using Animal Cell #14 Split, AquaBlack fights Yohane on her own but nearly gets overpowered by her, especially when she hurting herself while attacking her. Almost on the verge of defeat, the rest of the Aqours Rangers arrive, with AquaYellow telling her that she is still their favorite fallen angel no matter what. After AquaBlue gives her Animal Cell #21: Armadillo Armour to become Armoured AquaBlack, AquaBlack stabs Yohane's crystal chest, finally being free from her connection and defeats her.

Alongside her team, AquaBlack becomes Super AquaBlack.

In Episode 30, Yoshiko decides to help Riko get over her fear of dogs in order to defeat Demon Hound. Super AquaBlack fights against Demon Hound while convincing Super AquaWhite and that her hatred will lead nothing but use it overcome her fear. With that, Super AquaBlack gives Super AquaWhite Animal Cell #21 for the latter to become Armored AquaWhite.

In the final battle, Yoshiko, Hanamaru, Ruby and Leah split up from their team. They then encounter a revived Demon Underling. AquaBlack protects AquaYellow from Underling's Lightning Blast, almost getting killed. She confesses to her that she loves her, which AquaYellow replies that she felt the same way.