Tsukasa Amakawa (天河 司, Amakawa Tsukasa) is Mizue Hotori's brother and Tadase Hotori's uncle. He also known as Louis Antoinne Tsukasa in the manga, is the founder of the Guardians of Seiyo Academy, so he was the first King's Chair. Most people refer to him as "Chairman". After he graduated, he left behind certain artifacts for the next generation of Guardians; the Humpty Lock and an artbook called The Heart's Egg. He is now the principal of Seiyo Academy and works part-time in a planetarium.