Mizuno Ami is a very studious and super-intelligent girl, who likes to read, and has ambitions to become a doctor like her mother. She tolerates very little tomfoolery, and is very strict when it comes to studying(she is the reason that both Tsukino Usagi and Kino Makoto got into High School).

Ami's family consists of her and her mother, who is a doctor, and her father,(who doesn't live with them,)who is an artist. Ami and her mother live in a mansion in Tokyo. (In the crappy DiC dubbed ver of Sailor Moon, she lives in an apartment.)

Ami is also the superheroine, Sailor Mercury. When transformed, she has the power to control water and ice, and has a powerful mini computer that she uses along with her visor to track things and learn about their weaknesses and other such things.

When Tsukino Usagi and Luna first saw Ami, they thought she was one of the enemy, an agent from the evil forces that were attacking the Earth at that time. But when she herself was attacked by the enemy, because they wanted her energy, she transformed into Sailor Mercury!