SeiUsa

SeiUsa is the Femslash ship between Seiya Kou and Usagi Tsukino from the Sailor Moon fandom.

Canon
Their first encounter was at the airport in episode 173, when Usagi is seeing Mamoru off, who was going to study abroad, and who had just proposed to her. Seiya had just landed and while wandering away from screaming fangirls, she walked past Usagi. While Usagi didn't take notice of her, Seiya sensed a strong mysterious power surrounding Usagi.

The following day Seiya sees Usagi again at a park, though Usagi doesn't recognise Seiya, which surprises her, since she is the lead singer in the popular idol group "Three Lights". Not long after, Seiya and the other Three Lights also attend the same school as Usagi. She sits behind Usagi in class and calls her 'odango-atama' like Mamoru does. Usagi gets annoyed by Seiya's constant teasing but the more time they spend together, the more their relationship develops and they become close in no time.

In episode 181, Seiya manages to ask Usagi to go out with her, without Usagi knowing it was actually a date. They have a fun playful time together at the zoo, and they even hug each other accidentally. Usagi's heart is constantly pounding, and starts to realise Seiya might have something for her. Seiya advances towards her, and Usagi thinks too much into this. After realising she simply wanted to ask her to dance at the disco, she becomes slightly embarrassed. The lights go out due to a power outage and Seiya takes Usagi into her arms and tells her that everything would be alright.

This outage however wasn't an accident, but rather caused by Sailor Iron Mouse, whose target was Seiya. Amidst the battle, Seiya had transformed into Sailor Star Fighter without Usagi's knowledge. In this form, Seiya realises that Eternal Sailor Moon (not Usagi) knows Seiya. Things are starting to get complicated, though in the end Seiya convinces herself Usagi can't be Sailor Moon. Seiya then gives Usagi a little bear keychain as a thank you gift for spending the day with her.

In episode 187, the girls from Usagi's school who formed the Seiya Fan Club weren't impressed by Seiya and Usagi's closeness. The leader of the fan club challenges Usagi and Seiya in a softball match, announcing that if their team loses, they must 'break-up'. Usagi denies the fact they're together, but it didn't seem to do any good. Usagi was pretty terrible at softball and Seiya patiently trained her to catch a ball all afternoon. Soon the night sky takes over and the two take a break while looking at the stars. Seiya tells Usagi that she believes in her and that she doesn't want to lose the game. The truth was, Usagi didn't want to lose either and she tries her best which causes her team to win.

Things start to get bad in episode 188, when Aluminum Siren sets a trap for Usagi (after knowing her true identity as Sailor Moon). In order to protect her, Seiya transforms in front of her, revealing her secret identity. Usagi is shocked by the discovery but realises she has no other choice but to transform as well. Confusion, anger and sadness takes place, with the Sailor Starlights conflicting with the Senshi of the Solar System. Despite their differences, Seiya couldn't stop thinking about Usagi, she still believed in her. Usagi is also saddened because she doesn't want their friendship to end.

Seiya feels that Usagi is very important to her, even more important than her mission to find her princess (Princess Kakyuu). This often creates a quarrel among the Three lights, since she's the only one who trusted Usagi, constantly defending her.

Fanon
SeiUsa is one the most popular ships within the Sailor Moon fandom. It's also commonly pitted against the MamoUsa ship.

Seiya loves Usagi as Usagi and when she didn't want her to be Sailor Moon, it was because she thought that would make her an enemy and she didn't want her as an enemy because she liked her. And then when they found out about each other's secret it only made Seiya love Usagi more, knowing they were similar and that Usagi is fighting to protect her planet. Although they start very distanced, as Usagi also started with Mamoru, eventually Usagi softens up to Seiya and becomes friends with her. A simple glance at their date episode shows how much fun these two can have together. They are both more similar in many ways. Seiya also wanted Usagi to hear her song after she found out she was Sailor Moon, so that she could be completely honest with her and so she could truly understand why she was there and what her whole purpose was. And during the final fight with Galaxia, the amount of times Fighter took a hit for Usagi, covered her, held her to make sure she wouldn't get hurt just shows how much Seiya cares for Usagi. Even Sailor Saturn made the statement that Seiya's love for Usagi was still a light of hope.

Fandom
FAN FICTION