Depending on who you ask, each clan is a good guy and a bad guy.
Crab (Good): Defenders of the Great Wall of the South, devoted protectors of Rokugan against the monstruosities of the Shadowlands
Crab (Evil): Bloodthirsty berserkers believing the end justify the means.
Crane (Good): Paragons of the Samurai virtues, always striving for perfection in all things, from art to warfare.
Crane (Bad): Manipulative sycophants who bullies those who disagree with them with death threats (aka duels)
Dragon (Good): Monks and Scholars devoted to contemplation and introspection, always looking for the hidden truths.
Dragon (Bad): Isolationists who prefers to hide and let the rest of Rokugan deal with its various problems while flauting their superior understanding of the universe.
Lion (Good): Ultimate followers of Bushido and Honor. They always respect their word and they participate like no other to the Rokugan war effort to protect it against internal and external threats.
Lion (Bad): Warmongers who uses their military might to establish their dominance on the rest of Rokugan.
Phoenix (Good): Scholars and Priests devoted to research for the betterment of mankind, as well as a greater understanding of the different Realms of existence.
Phoenix (Bad): Power-hungry spellcasters who jealously keep their discoveries secret and never hesitate to willingly uncover knowledge man wasn't meant to know.
Scorpion (Good): The most loyal followers of the Emperor, willing to sacrifice their own lives and honor to protect Rokugan.
Scorpion (Bad): Miachiavellian manipulators twisting and corrupting the very concept of honor.
Unicorn (Good): Courageous and honorable explorers, always greeting others with open arms and an open heart.
Unicorn (Bad): Opportunists with no sense of honor, willing to forget millenia of traditions for a momentarly advantage that can be disastrous on the long run.