Sailor Moon is the main heroine of the show and is the leader of the Senshi. She makes her first appearance in Sailormoon episode #1. Though a klutzy, ditzy girl who whines a lot and tends to be cowardly, Tsukino Usagi is destined to greatness. She is the most compassionate and caring of all the Senshi, and never fails to believe in her comrades in times of need. As her role as a super heroine, she transcends to differents levels within her life: Sailor Moon, Super Sailor Moon and finally Eternal Sailor Moon. These are not her only transitions, she also learns that she is the Moon Princess and in the future becomes Neo-Queen Serenity. This is a big responsibility for a young girl and at times she is very reluctant to accept her destiny. Arguably, Sailor Moon is the most powerful of the Senshi and is the keeper of the Maboroshi no Ginzuishou (The Illusion Silver Crystal), along with other magical items. Nonetheless, the Senshi protect her because she is the Moon Princess and will be the future Queen of Crystal Tokyo. As time goes on, through her experience, training and personal growth, Usagi becomes more comfortable with her role as Sailor Moon and becomes more mature.

Tsukino Usagi lives in a house in Minato-ku (Tokyo, Japan) with her family: Tsukino Kenji (father), Tsukino Ikuko (mother) and Tsukino Shingo (little brother). Her parents are caring and loving to both Usagi and her brother. But they can be strict on Usagi at times, like when it comes to her grades in school, they only want the best for her. Usagi and Shingo have a relationship like most siblings do; they are forever picking on each other, but despite their fighting and teasing, they do care for each other. Before she learns of her destiny, she lives a normal life just like any other teenager. She is attending Juuban Junior High School, second year, class 1, when she is first introduced in the series, then later in the series she graduates to Juuban High School. School is not one of Usagi's strong points and she tends to get sidetracked from her studies easily. She is often late, gets low grades and would rather be doing other fun things instead of school. Mathematics and English are her least favorite subjects, but she does enjoy home economics. Usagi's interest are typical for a teenager, she loves to play video games, go shopping with her friends and read mangas (comics). She also enjoys eating and she will eat a lot. There isn't much that she doesn't like, but one food she is said to dislike is carrots. She is klutzy and a crybaby but tries to do her best. She has a hard time staying focused on the important matters at times, but in the end she always pulls through with the help of her good friends.

In her past life, Usagi was Princess Serenity of the Moon Kingdom during the Silver Millenium. It was a peaceful time during the Silver Millenium, that is until an evil force known as the Dark Kingdom came to destory the Moon Kingdom in hopes of gaining control of the Universe. They did indeed manage to destroy the Moon Kingdom with a massive attack, but in the end Queen Serenity, her mother from the Silver Millenium, was able to defeat the Dark Kingdom. She used the remaining energy she had to summon what bit of power that remained in the ginzuishou. With that power of the ginzuishou, she was able to trap the seven evil warriors that worked for the Dark Kingdom. By doing this, the Ginzuishou was shattered into seven pieces forming the Nijizuishou (Seven rainbow crystals), each one containing one of the evil warrior's spirits within. Sacrificing her life and what was left of her Kingdom, Queen Serenity sent her daughter, Princess Serenity, Prince Endymion, the Senshi and many others of the Silver Millenium to another life to be reborn in hopes they would have a happier life. She also sent her two cat advisors, Luna and Artemis, who were instructed to be the guardians of the Moon Princess and the Senshi. Should the need arise, Luna and Artemis would know what to do to help get the Senshi ready to defend their world.

In the future to come, Usagi will be Neo-Queen Serenity of Crystal Tokyo. Her and King Endymion (Mamoru) rule Earth side by side. Also, they both have a daughter and name her after Usagi, but they call Chibi-usa as a nickname. Chibi-usa is sent back through time by Sailor Pluto to find the Ginzuishou and to be protected by Sailor Moon and the Senshi/Scouts. Chibi-usa's grand entrance, was her falling out of the sky and landing on Usagi's head during a special moment with Mamoru. Instantly, Mamoru and Chibi-usa have a unique bond and connection to each other, by they don't understand why. This drives Usagi crazy and she gets very jealous of Chibi-usa because she doesn't understand what is going on. In the beginning, Usagi and Chibi-usa don't get along to well, perhaps its because they are both so much alike. To Usagi, Chibi-usa is just a spoiled little brat who getting in between her and Mamoru. For a while they all don't know that Usagi and Mamoru are the future parents of Chibi-usa. But after time, a bond of love grows between Usagi and Chibi-usa and Usagi will do anything to protect her.

And this is how the adventures of Sailormoon begin. Usagi, late as usual is on her way to school when she notices a group of kids picking on a black cat. Instantly Usagi goes to help and chases off the kids. She picks up the cat to comfort her and then removes a bandaid from the cat's forehead, revealing a yellow crescent moon. The black cat, who is Luna, leaps from Usagi's arms and is still shaken from the whole ordeal. Realizing the time, Usagi hurries off to school leaving Luna there to wonder if Usagi is the one she is looking for. Luna trails Usagi, watching her from a distance until she decides Usagi is one of the Senshi. Later that evening after school, Usagi is laying on her bed resting when Luna sneaks into her room through her window. Usagi gets startled by the cat, then flips out when she learns that Luna is able to talk to her. Luna tells Usagi that she was been searching for her, that she is Sailor Moon and its her desinty. At first Usagi doesn't believe it. Luna gives her a beautiful magical brooch that transforms her into Sailor Moon. Usagi is very reluctant in her role as Sailor Moon and is unsure of herself, but Luna helps her, giving her guidance and advice.

Usagi is normally cheerful, sunny and outgoing, but is known to have mood swings. She is an emotional person which happens to be a cancer-like trait. Because her heart is so big, she can get her feelings hurt badly. One of Usagi's strongest assets is being a loyal friend and her love for all life. She truly cares for everyone and even more so for her family and friends. Usagi will often sacrifice her own needs for others. If someone is in trouble she will put her own life on the line to help them. Usagi has a knack for making friends with just about anyone, perhaps it's the aura of love and friendship that surrounds her. She is a good listener and will do her best to offer advice when she is able. She isn't afraid to speak up, but will sometimes speak without thinking first.

Usagi is a hopeless romantic who daydreams about the guys she has crushes on. Her first crush that we become aware of is on Furuhata Motoki, the manager of Crown Game Center. Then she develops a crush on Tuxedo Kamen after their first meeting. In the beginning, she is not aware that Tuxedo Kamen is really Chiba Mamoru. In the anime (Sailormoon the first season), Usagi and Mamoru don't get along too well at first. Mamoru comes off being rude and mean to Usagi. He sees her as a young kid and teases her. Mamoru gives her the nickname O-Dango-Atama because of her unique hair style, which Usagi can't stand at first, but later in the series it becomes a name of endearment and is used by others. As time goes on, a fondness grows between them. Their relationship together doesn't take place until they both learn their secret identity and about their past lives. In the manga it is different, Usagi and Mamoru grow to care for each other almost at the start. In Sailormoon R the second season, due to having everyone's memories wiped after defeating the Dark Kingdom, Usagi gets a crush on Tsukikage no Knight, who once again is Mamoru, but is his spirit self. But after she regains her memory, she knows that Mamoru is her true love. Throughout the series, Usagi will have her crushes here and there, but her heart always remains true to Mamoru.

Being couragous is not Usagi's strong suit. At first she will linger back being overwhelmed by whatever situation she may be in. It takes her a moment to work up her nerve and courage, but once she does, she will not back down. And if it's a friend is in need, she doesn't even hesitate to aid them. Usagi's powers tend to come from her magical brooch, the Ginzuishou and other magical items she has, unlike the other Senshi. The others are perceived to have the power within them once they transform. Being the Moon Princess, she is very attuned with the moon and if you look deeper into Usagi, you will notice that there is something about her that is almost mysterious. She has a certain amount of empathy about her. She can sense what a person is feeling whether it be happy or sad. She is not able to read minds or anything like that, but maybe this gift is what makes her such a good listener. She can also find the good in someone when no else can and even sometimes help them to find it in themselves. This could get her into trouble and has at times. Because she is able to see that little bit of good, she can be too trusting and giving. Even though she can see it, the others may not see it within themselves and use her trust against her.

Usagi is not one to be alone, she likes being with her friends. It's almost like she has a need to be around people and needs to be liked and loved. One of her closest and best friends since childhood is Naru. They remain close friends throughout the series and many times Usagi is coming to Naru's aid as Sailormoon. Naru never learns that Sailor Moon is really Usagi. They both go to the same school along with Umino Gurio, who has a crush on Usagi. But Usagi is not interested in him except as a friend. When Usagi meets the other Senshi, a strong bond of friendship is formed. They have their fights from time to time. Usagi and Rei are forever picking on each other and sometimes seem like they are sisters. Usagi isn't close to the Outer Senshi like she is with the Inner, she holds a high respect for them, the exception to this is Hotaru who she is more affectionate to.

Just like any of the other Senshi/Scouts, Usagi has her flaws. The one she is most known for is her crying and whining. As mentioned before, she is a very emotional person and can take things to heart. Klutzing out is yet another one of her traits, but in the manga, she doesn't seem to be us much of a klutz as she is in the anime. Usagi has a tendency of going through phases of things she wants to do or likes. Some examples are: wanting to be a singing star, going on a diet, practicing to be a Princess and studying more to make Mamoru proud of her. This is normal for teenagers, but Usagi tends to take it to extremes at times and eventually she will lose interest and move onto something else never finishing what she started. She doesn't do this all the time, but does enough that Luna and the others notice it and later in the series it is mentioned. In the manga, Usagi is protray a bit more aloof and doesn't seem to be as goofy acting as she is in the anime.

Usagi is known by many different names and some of them have a meaning behind them. In most cases, except for a few and we will mention those, all of her names relate in one way or another to the moon. In Japanese, Usagi means 'rabbit and Tsukino means 'of the moon'. Like we mentioned before, there is an Asian legend of the 'rabbit on the moon'. Tsuki is the Japanese character (letter) for the moon and it appears in the Japanese word 'getsuyo-bi' (monday). In Japanese, Monday is known as 'Moonday'. Her North American name, Serena, also relates to the moon. It is derived from Usagi's Japanese name as a princess, Serenity or Selenity, which can be spelled either way. There isn't a distinction between the sounds of 'l' and 'r' in the Japanese language. There are two origins to this name. The first is the reference to the Sea of Serenity on the moon. In the manga (volume 3), it states that the ruins of the Moon Kingdom are located there. The second reference is to Selene, the Greek Moon Goddess. The mythology behind this is that she loved Endymion, which happens to be the name of Mamoru as a Prince and later the King. This reference was lost in the North American dub, because they call him Prince Darien. Odango atama is a nickname that was first given to her by Mamoru due to her unique hair style. It translates to 'dumpling head'. Odango's are a Japanese delicacy and since the North American's don't have them, they translated that nickname into 'Meatball Head'. Later in the series once Mamoru and Usagi are a couple, he calls her Usako, which is used as a term of endearment. 'Usa' is a shorted version of Usagi and 'ko' in Japanese means child or baby.