Tomono-Kai (which means "Association of Friends") is the parent association of Nishimachi.  All parents of students at Nishimachi are members of TNK.  The main purpose of TNK is to support efforts by the school to increase communication among the various segments of the school community and to create a sense of unity.  In addition, TNK sponsors a variety of cross-cultural programs and social functions, and raises funds for the school for the benefit of Nishimachi students.  All proceeds from the Tomono-Kai Shop go to TNK and Outreach scholarship.