Location for "The Search for Oyamatsumi" in Cannon of Vengeance?

[Boon: Queer Chaos]

Does anyone know where the hell to find the "The Search for Oyamatsumi" quest when playing cannon of vengeance or it's equivalent? I remember from the original game that quest is available after you beat Surt in Chiyoda which unlocks Oyamatsumi for fusion. Since vengeance plays out a bit differently has anyone figured out how to unlock them? Wanting to fuse Konohana Sakuya after doing "Sakura Cinders of the East" but I can't due to her fusion recipe requiring you to have Oyamatsumi already 😓

[Boon: Queer Chaos]

UPDATE: The quest that needs to be completed for vengeance is "Special Training: The Kunitsukami" and can be found inside the tokyo diet building.