fujimaru ritsuka (female) (imperial robe)
Female Ritsuka in her version of the special costume crafted by servants in Fate/Grand Order's chapter Realm of the Thanatos Impulse, Traum. It was only possible to use it during the story, it's not a Mystic Code.
For Male Ritsuka's version, see Fujimaru Ritsuka (male) (Imperial Robe).