Count Mott, known as Mott of the Wave, is a Palace messenger sent to the Academy every now and then. He is a Triangle mage and in the anime, uses water as a medium for attacks. Louise describes him as being arrogant and told Saito that even Guiche is not on good terms with him as well.
He is after the "Summoned Book" (an old porn book), which is a treasure of the Zerbst Family. In the anime, he told Saito that for him to release Siesta from being his servant, Saito must get the Zerbst Family treasure and hand it over to him. As Saito asked Kirche about it, Kirche agreed to give it to him, in exchange for going out with her, which he angrily refuses. So, without the book, he went back to the Mott Palace to take Siesta by force and drew a sword. Saito was saved by Louise, and Louise asked for forgiveness for Saito's actions, and it was then that Kirche introduced herself as the daughter of the Zerbst Family and handed the "Summoned Book" over to Count Mott in order to settle things and get back Siesta.