Yui Kanakura

inherited the title of a don of a large Chinese mafia group, Yui simultaneously works as a homeroom teacher. It can hence be implied that she has a great sense of responsibility and industriousness. This is further magnified as stated by Ie - Yui's personal aide - that Yui had united all the scrambled members of her faction in a mere two years during her jurisdiction and had maintained the stability within the Char Siu, also implying that Yui is fearsome and a very powerful figure.