Ruka is very brash and acts as a tomboy compared to Itosu who has a totally opposite personality compared with hers. She acts without thinking ahead, going straight into battle against her opponents which easily lets Black Lotus to defeat her swiftly.
However, she is very polite in the real world as seen during her meeting with Kuroyukihime and she holds high regards for her master and the rules that he set for her and Itosu.
Ruka became the child of her master Crimson Kingbolt after he moved to Okinawa. After becoming a burst linker, she became a parent for Itosu and the two are inspired to increase the number of burst linkers in their community.
Ruka has a tan skin color and is of medium stature. She has red hair and magenta eyes.
Dusk Robber (Side Story)
Ruka's Duel Avatar is Lagoon Dolphin. Lagoon Dolphin has a humanoid shape that is designed and based on a dolphin. Her whole entire body is colored in shades of blue. She has two light blue eyes with a blue helmet. Her body has lighter blue armor around her shoulders, torso, arms and legs. The armor is stylized with dolphin shaped fins on her arms, back of her shoulders and sides of her legs. In her Marine Mode, her fins on her armor grow noticeably longer.
Lagoon Dolphin utilizes close combat moves with her fists and legs as seen in her battle against Black Lotus. However, during her fight with Sulfur Pot the environment changed into the ocean. She is then able to utilize an ability known as Shape Change that allowed her to change her form which she calls "Marine Mode." In her Marine Mode, her mobility and power is greatly enhanced.
- Tidal Wave: Lagoon Dolphin focuses energy into her two fists &releases them into a barrage of fists formed from water.
- Her English voice actor voices Silica in the English dub of Sword Art Online.