Master Sensei of a secluded order of Tsukiyo devotees, formerly known as Hisui (a title given to the current village master, meaning 'Jade') lived high in the mountains of Minkai. His order was composed of many outcasts of society, including quite a few "helltouched" as he. He taught others the ways of shadows and spirits, raising them to be guides for the souls destined for Father Moon's embrace.
Midori-san had a standing debt with a venture-lieutenant of the Pathfinder Society after the Pathfinder saved his life many years ago. When the Pathfinder requested a capable student to carry out tasks requiring a subtle touch, he sent his most promising student: Baru.
Baru was one of his brightest students, and was sent to fulfill an old agreement between his mentor and the Pathfinder Society of the west. He obeyed well. However, it seems it was not quite ready for the challenges of the world. While investigating a murder at a Varisian fair, Baru was found and assailed by ne'er-do-wells intent on hiding their illicit shiver trade. He was unable to escape with his life.
In order to fulfill the debt, Midori has passed on his role in the village and set off for Absolom himself. He could not bring himself to send another student in his place. Having given up his name upon become Master Sensei, he now goes by simply Midori, meaning "green one."
