The game implements rules of Japanese mahjong, including Dan么nine (断么九) and Dora. The 21 available computer-controlled opponents have background music and character dialogue that can include puns.

The characters in the game include the following individuals listed in order.

Oda Nobunaga – A 16th century warlord from the Warring States period.
Toyotomi Hideyoshi – A general from the Sengoku period.
Tokugawa Ieyasu – First shōgun of the Tokugawa shogunate. Often does Tenpai (聴牌).
Cleopatra – Last pharaoh of Ancient Egypt.
Yang Guifei
Ono no Komachi – A Waka poet from the early Heian period. Does fun and bright mahjong.
Sakamoto Ryōma – Samurai and politician from the Bakumatsu period.
Minamoto no Yoshitsune – A general from the late Heian period.
Miyamoto Musashi – Expert swordsman and rōnin. Always fails when trying a one-shot reversal.
Zhuge Liang – The most accomplished strategist of the Shu Han Chinese state during the Three Kingdoms period.
Nostradamus – Famously published collections of prophecies.
Kou Shibusawa
Genghis Khan – Founder and emperor of the Mongol Empire. Plays mahjong in a secure and dignified manner.
Napoleon – A French emperor.
Julius Caesar – A Roman general and statesman. Has a brutish attack but also exhibits human weakness.

hum... "Play mahjong with KOEI historical figures" That sounds like an interesting premise for a franchise. (Nobody has any of them on their shelves!) Doubt any are in english, though