A rectangular plaque of smooth white stone is recessed into a wall of rough, weathered red brick. The Japanese inscription 'みなと異人館' is carved deeply into the center and filled with black ink, identifying the structure as the Minato Ijinkan. Sunlight from the upper right creates defined shadows within the strokes of the characters and along the uneven mortar joints of the surrounding masonry. The texture of the bricks varies from porous and pitted to smooth and fired, contrasting with the pristine surface of the signage.