What is chaji?

Some articles on chaji:

Japanese Tea Ceremony - Usual Sequence of A chaji
... of one host and a maximum of five guests is considered the most formal chaji ... The following is a general description of a noon chaji held in the cool weather season at a purpose-built tea house ... is displayed a hanging scroll which may allude to the season, the theme of the chaji, or some other appropriate theme ...
Japanese Tea Ceremony
... Tea gatherings are classified as chakai (茶会?) or chaji (茶事?) ... A chaji is a much more formal gathering, usually including a full-course kaiseki meal followed by confections, thick tea (濃茶, koicha?), and thin tea ... A chaji can last up to four hours ...