Long before the Queen Serenity that we know ruled the Silver Millenium, Janus orbited our sun between Pluto and Nemesis. Also known as Pluto's twin sister, Janus was located just past Pluto, until it was struck by a comet. The comet split Janus in two; both pieces sailed through the outer planets until Saturn's gravity forced them to begin orbiting it. We now know them as the Saturn's moons, Janus and Epimetheus.

Most of the people were made up of outcasts, whom had traveled to Janus long ago. They weren't particularly accepted by the people of the other planets- save for those of Saturn and Pluto- because they were unable to use elemental magic. The other Janusians were emigrants from Pluto who wanted to start over, free of whatever obstacles they had on their home planet.

Unlike the Sol system's other planets, the inhabitants could not use elemental magic- as stated above. Their abilities mainly revolved around the healing arts of herbs, plants, etc., and incantation sorcery. One of the most useful incantation magics was the summoning of underworld beasts to offensively attack opponents.

Janus, much like Venus, was ruled by a queen; she was named Ima. Her daughter, Princess Toki, had fallen in love with the Crown Prince of Pluto, Juyo, and vice versa. A marriage was arranged for the prince and princess, combining both the Plutonian and Janusian kingdoms. After the marriage, the Plutonian king and Janusian queen passed the thrown to their children. Both kingdoms prospered from the marriage and their leadership.

Two years after the marriage, the happy couple had a daughter, whom they named Setsuna. To solve the problem of having two kingdoms, they decided to have two children; Setsuna, being their first child, would inherit the Plutonian kingdom, while their second child would inherit the Janusian kingdom.

Unfortunately, a small skirmish broke out between the Plutonians and Neptunians six months later, and King Juyo was killed.

Later, it was discovered that King Juyo was not killed. In actuality, he was the human form of the God of Time, Chronos.

After a year of mourning for the King of Pluto, the former King and Queen of Janus decided to arrange another marriage for their daughter- who was busy running two planetary kingdoms- to a lord on solitary moon of Pluto, Charon. Queen Toki and the lord- Chronos in disguise, again- were married and nine months later, they had a daughter, Shizuka, who was to become ruler of Janus.

When Princess Setsuna was sixteen, the symbol of Pluto appeared and she was declared SailorPluto, Senshi of Time. In reaction to Pluto's symbol energy, Shizuka's symbol, a golden hourglass, also appeared on her forehead. It was declared that she would be the next SailorJanus, Senshi of the Corridors of Time.

At age eighteen, Setsuna was sent to the Gates of Time to start her duty as SailorPluto*. Two years later, Shizuka, eighteen, traveled to the Corridors of Time to begin her duty as SailorJanus. There she is to remain, watching the events of those gone and those coming, until called on by SailorPluto or the gods to fight.

When the Negaverse attacked the Moon Kingdom a thousand years ago, SailorJanus, at that time, was on the Moon as well. She was summoned as representative of both Janus and Pluto. So, when Queen Serenity used the Ginzuishou and sent everyone to be reborn, Janus was sent as well.

Up until becoming SailorJanus, Shizuka lived with her grandparents- her parents were murdered by a mugger when they were abroad- in the Ikebukuro District of Tokyo. At 15, Janus' symbol appeared. She battled crime & youma until age 17, when she was summoned by SailorPluto to take her place in the Corridors. She also watches the Gates when Pluto is on Senshi business.