The card game design was chosen so people can relax and enjoy a game while drinking beer. Or play drinking games with them.
The calendar uses the same imagery as displayed in each card suit. The animal in january suit has been used on the january calendar page, and so on.
This wall hanging calendar format was chosen to resemble the japanese parchment wall hangings, since they come in this shape, and the symbols and writing has been displayed in this way, similar to japanese scripture writing.