Nine colored circles arranged in a grid pattern represent the Tokyo Metro lines, each labeled with a single letter (G, M, Mb, H, T, O, Y, Z, N, F) in clean, modern typography against a soft peachy-beige background. The composition is orderly and graphically striking, presenting the transit system as an accessible visual reference with its Japanese title "東京メトロ" and English subtitle at the top. Printed on smooth white card stock and made to order, artwork on the front, blank inside, envelopes included in every set. A handwritten note that arrives as an independent artist's work.