TV-Series
Description
Yae Kokonoe hails from the Divine Nation of Eashen, reminiscent of feudal Japan. Born into a samurai family, she is the daughter of respected swordsman Jubei Kokonoe, bodyguard to Lord Ieyahsu Tokugawa, and Nanae Kokonoe, with an older brother, Jutaro Kokonoe, also a skilled swordsman. The family name "Kokonoe" signifies "nine-fold," while her given name "Yae" means "eight-fold," reflecting a naming tradition using number kanji.

She departed Eashen to train as a swordsman in the Kingdom of Belfast. There, a confrontation with ruffians led to her meeting Touya Mochizuki, after which she joined his adventuring party. Initially, her combat style showcased exceptional swordsmanship with a katana, often wielding a single blade despite carrying two, demonstrating above-average reflexes and accuracy, such as stunning a dullahan-like monster by throwing its head at its body.

Her personality embodies samurai values, prioritizing honor, dignity, and dedication to training and allies, displaying intolerance for injustice and occasional impulsiveness. A significant trait is her high metabolism due to swordsmanship energy expenditure, resulting in substantial food consumption, sometimes linked to stress, particularly regarding romantic matters. Despite her combat prowess, she exhibits shyness about femininity and inexperience in love. She shows aptitude with children, later noted as the most skilled among her peers in child-rearing. She uses the samurai speech conventions "sessha" as a first-person pronoun and "gozaru" as a sentence-ender, a trait omitted in the anime.

Her capabilities evolved significantly. After becoming engaged to Touya Mochizuki, she received an engagement ring enchanted with Null Magic spells 【Accel】, 【Storage】, and 【Transfer】, enhancing mobility and utility. As a Retainer of Moroha Mochizuki, she gained the "Dependent Trait" of Improved Fighting Power, a divine blessing boosting combat abilities. Her equipment includes a Mithril Daishō set commissioned by Touya and later the phrasium katana Tōka ("Transparent Flower"), possessing minimal mass, superior sharpness and hardness, regenerative properties, and the ability to accumulate ambient magic power. She also pilots the lightweight Frame Gear Schwertleite, equipped with phrasium blades.

Within the narrative, Yae developed romantic feelings for Touya. She later fought alongside Elze Silhoueska against him in a mock battle; their victory resulted in her formal engagement as his fourth fiancée. She became a founding member of the Bride Conference, managing Touya's marital relationships. Ultimately, she married Touya, becoming the Ninth Queen of the Brunhild Dukedom. She is the mother of Touya's firstborn child, Yakumo Mochizuki, who holds first princess status despite Yae's official rank as the lowest duchess publicly. Her astronomical association among the wives is the Moon, reflected in crescent moon motifs on her kimono.

Her character design features long black hair, often tied back with a large scarlet bow and accented by smaller white cloth pieces near her face. She wears traditional samurai-inspired attire: a pink kimono with white crescent moon patterns, dark blue hakama pants, a turquoise obi secured with a cyan bow, and modernized sandals, showing distinct stylistic influences.