TV-Series
Description
Meiya Mitsurugi originated from a childhood promise made to Takeru Shirogane during her last visit to a park before her planned adoption. After her parents and older twin sister died in an accident, she became the heiress to the Mitsurugi Zaibatsu, replacing her deceased sister. To avoid a political marriage, she negotiated a deal with her grandfather, Mitsurugi Raiden: she could marry Takeru if he independently remembered their promise and fell for her. Her sheltered upbringing initially fostered naivety, often leading her to resolve issues through wealth. Interacting with Takeru and classmates gradually developed her "common people's sense." She possesses a strong sense of righteousness, opposing cheating or underhanded tactics, and demonstrates exceptional skill in the "Mugen Kidou" sword style, applicable even with objects like lacrosse sticks.

In an alternate timeline affected by a BETA alien invasion, Meiya's background diverged significantly. Born Koubuin Meiya, she and her twin sister Yuuhi were separated due to superstitions viewing twins as bad omens. Her family gave Meiya to the Mitsurugi family while Yuuhi remained with the Koubuin regent house. Named for "darkness" (contrasting Yuuhi's "light"), Meiya was destined as a disposable body double for Yuuhi, living under house arrest while training in combat, etiquette, and shogi. Tsukuyomi Mana, sent by Yuuhi, became her guardian and close confidante. During the BETA invasion, authorities relocated Meiya to Sendai for safety. Later, serving as a political hostage to prove Japan's commitment to the Alternative IV project, she joined Yokohama Base's Squad 207B. Her resemblance to Shogun Yuuhi caused others to treat her stiffly, a dynamic she eventually accepted. Her reunion with Takeru, who recognized her immediately, set key events in motion.

Meiya's core traits remain consistent across timelines: she upholds Bushido principles, values honor, and faces conflicts between her duties as a soldier and her obligations to Japan. In the BETA timeline, she excels in melee combat and pilots Tactical Surface Fighters (TSFs). Her status is hinted at by privileges like a gifted Type-00R Takemikazuchi TSF and a detachment of the Imperial Royal Guard.

Takeru's role as a "Causality Conductor" infuses Meiya with memories and emotions from their interactions in other timelines, including experiences as lovers and parents. She dismissed these memories as dreams, amplifying the tragedy of her eventual fate. During key events, she served as Yuuhi's body double, nearly quelling a rebellion by convincing a rebel leader to stand down. Her relationship with Takeru strained when she temporarily lost respect for him after he obsessively blamed himself for the XM3 trial failures, contributing to his temporary departure. Upon his return, she struck him tearfully for leaving without explanation, though their bond strengthened afterward. This culminated in emotional pain when Takeru, oblivious to her feelings, asked her to be his "Noble Confidant," prompting her quiet refusal. She further suppressed her emotions upon witnessing Takeru with Sumika Kagami and overhearing his flirtations with his girlfriend.

During Operation Ouka, Meiya became the last surviving Valkyrie squad member. She interrupted Takeru's negotiation with the BETA Superior, initiating a self-destruct attack to save him. This failed, leading to her death when Takeru was forced to fire upon her along with the Superior.