A Girl's Most Important Event

"A Girl's Most Important Event" (それは☆乙女の一大事) is the first episode of the anime series My-HiME.

Plot
On the upper deck of a cruise ship, Mai Tokiha joins her younger brother Takumi, sitting on a bench and looking at the sky. Mai notices a red star-like twinkle near the moon; she has seen it before, yet Takumi is unable to spot it. Soon, they forget about the star, as their attention is diverted to a body floating in the water lifelessly. It is a young girl in a school uniform &mdash; Mikoto Minagi.

The rescue team lifts the girl on a boat. She is tightly holding a big sword, and as they release it with the help of Yuuichi Tate, strange signs appear on the sword, and it emits an energy blast, cutting the ropes supporting the boat. The boat and the rescuers fall into the water, along with the sword, which drowns; Mikoto, however, has been pulled aboard the ship by Yuuichi.

Yuuichi asks for someone to perform CPR, but nobody volunteers; as he prepares to perform it himself, Shiho Munakata pushes him out of the way, suspecting him of trying to take advantage of the breathless girl. Seeing this, Mai volunteers to perform CPR; with her aid, Mikoto spits out water and starts breathing, and is taken away.

Night comes. Natsuki Kuga, a dark-haired girl with a bandage on her left arm, is on a small boat, looking for Mikoto. The boat operator suggests that she was picked up by the ship Mai is on, while looking at a strange birthmark on Natsuki's back (the HiME sign).

Meanwhile, Mikoto is sleeping in the sickbay. She pulls her hand, and the sword that previously drowned is pulled into the room, still wet.

Mai is in her room. She checks and picks up Takumi's pill box and then notes the birthmark on her chest, identical to the one that Natsuki has. Furthermore, Mikoto also has a similar birthmark on her right arm. She is worried if the CPR performed on Mikoto counts as a first kiss, trying to persuade herself that it does not. Having no other spare clothes left to replace her wet T-shirt, Mai is forced to change into her school uniform, packed into a red bag with the letter "F". She descends downstairs, where Takumi, Yuuichi and Shiho are having a drink, and all four realize that they are transferring to the same school: Fuka Academy.

While Natsuki's boat catches up with the ship (with Natsuki now wearing a body suit with a full-face motorcycle helmet), Yuuichi and Mai are heading for the bridge at the captain's request. As they stop and begin insulting each other, a glimpse of Natsuki jumping while riding some kind of mecha-dog briefly appears in the window. Natsuki, faceless, jumps in through the window, knocks Yuuichi unconscious, materializes a pair of pistols in her hands and knocks out the door to the sickbay with Mai lying on the floor helplessly. Mikoto, however, is not in her bed; hanging from the ceiling and holding the sword, she jumps on Natsuki.

Meanwhile, back in the hallway, Yuuichi recovers, thinking it was Mai who knocked him out. Natsuki and Mikoto, fighting, fall through the floor into the garage, along with Mai, who uses the opportunity to hide behind a truck. Saying that she cannot "allow HiME to gather at the Land of Fuka", Natsuki summons her mecha-pet Duran, who fires &mdash; missing Mikoto, but causing a lot of collateral damage to the ship.

The captain decides to evacuate the passengers. Shiho is pushed on a lifeboat against her will, as Yuuichi is missing: he is looking for Mai. He soon finds her in the garage &mdash; wandering aimlessly, barely conscious, amid the fire and debris &mdash; and rescues her. However, when Mai recovers, she gives him a beating, mistaking his behavior for sexual harassment.

Suddenly, Mai remembers that she forgot Takumi's pill box, and runs to her room. Meanwhile, the fight between Natsuki and Mikoto continues on the upper deck. Yuuichi finds the box on the floor and picks it up; however, at the same moment, Mikoto activates the power of her sword, slicing the ship apart precisely between Mai and Yuuichi. Mai charges him with finding her brother and giving him the box, and, through the emergency hatch, climbs onto the upper deck &mdash; right where the battle is going; Mikoto, doing a backflip, falls on her.

Duran charges at Mai and Mikoto, and as Mai stretches her arms in terror, suddenly a wall of fire appears on Duran's way, knocking him back. Mai stares at the strange floating lights in surprise; Natsuki shoots at her, but the fire shield appears again, deflecting the shot. Natsuki curses and warns Mai not to go to Fuka Academy &mdash; otherwise, she claims, Mai will die. Natsuki then leaves with Duran; the part of the ship with Mai and Mikoto starts drowning from one side, and they both fall into the water, along with Mikoto's sword...

Not very far away on land, Nagi Homura watches the incident from a dome, and is excited by the impending arrival of "Mai HiME and one other person". He bows, starts dancing with a book on his head, and falls.

Morning comes, and Mai awakens. She is on land, with Mikoto lying beside her and her sword stuck in the ground, and with a flaming circle surrounding them. People around are looking at a trail leading at to the circle from the sea, as well as at herself; many of them are wearing school uniforms similar to hers, and Yuuichi and Shiho are among them. Mai is left trying to figure out what is going on...