Jiku

Jiku (Kakemono, or Kake-Jiku) is a visual symbol of the theme for the ceremony (Chakai). When the host decides to invite a guest for a bowl of tea, he or she makes a theme for the event, then creates or finds Jiku, a symbol to indicate the theme. Jiku should be placed in the area of the main wall (Toko no Ma).

The symbol would lead how the host and guests interact in the event, a conversation evolves around the subject of the theme.
It would be wise to refrain from casual talk during the ceremony to better appreciate the calmness and contentment in higher spiritual level. Poetry and Haiku come in quite handy at this time.

White Socks

Driving on Highway 1, when I used to take a Chanoyu lesson from Sensei in the Cost, I thought , he has one of the best Roji for his Chashitsu (tea room).

Walking on the Roji can be one of the best part of Chanoyu.
It's full of suspense and expectation for the event.

Don't forget to wear white socks (or tabi) to respect the ceremony.
It's the same kind of concept to wash hands and mouth before step into Chashitsu. The idea is to clean yourself in and out, it means mind and body.

Roji

Once you step onto the Roji, that's the start of ceremony.

But Japanese Tea Ceremony actually starts when you know, you are invited for the occasion.
It's the event that Teishu (host) and Kyaku (guest) performs to have a ultimate cup of tea for the spiritually higer level of moment. It's easy for me to meditate during the ceremony.

Cha-no-yu, the Japanese Tea Ceremony is a part of SADŌ (aka. Cha-Do) , the way of tea.
I suppose that it's the Zen like concept that anyone can practice and enjoy.

Cha-Jin doesn't have a clear definition, just in vague state like anything else in Japan. Chajin is a person who is into Sado, I suppose, all tea lovers can be a Chajin, but one has to be Fu-Ryu or Iki person.