AmiUsa

AmiUsa is the femslash ship between Ami Mizuno and Usagi Tsukino from the Sailor Moon fandom.

Manga
After school one day, Luna jumps on Ami Mizuno's head, wanting to investigate her. Usagi thinks that she isn't at all like what the rumors were saying about her, and decides to talk to her. Usagi notes to herself that Ami is kind of cute. Part of her desire to become friends with Ami is so that Ami would lend her super-genius abilities and help Usagi do well in school. Usagi then takes Ami to the Game Center. Ami tries out the Sailor V game, and gets the top score, to Usagi and everyone else's astonishment. A pen comes out of the machine for Ami, and Usagi wants one too, so she hits it until another one comes out. Ami laughs and says Usagi is pretty funny.

The next day, Usagi asks Ami if she wants to go out for ice cream, and is sad when she declines. Usagi notices Ami forgot her Crystal Disk and decides to return it to her. After seeing what the disk plays, she is determined to save Ami from being brainwashed by it.

90's Anime
Ami's introduction episode happens very similar to the manga, with only minor differences.

In the next episode, Usagi takes Ami to Harajuku to go window-shopping. Ami apologizes for not going out more, but Usagi tells her she doesn't need to. The two go around trying on things and laughing together. They end up going to a clock shop. Usagi is too broke to buy an alarm clock, so Ami offers to come wake her up every day. Usagi hugs Ami in glee, causing her to blush a little.

They later figure out that the Clock shop is causing everyone in the city to be rushing and impatient. Usagi, under the spell, transforms right away into Sailor Moon, and manages to make Ami want to transform as well. The two head into the clock shop and work together to find and defeat the enemy.

90's Anime

 * Episode 20: Usagi makes Ami change her mind about studying and plays on the beach instead.
 * Episode 45: Usagi is able to sense that Ami is dead even without seeing her.
 * Episode 51: Usagi holds Ami and blushes after saving the Inner Senshi from a Cardian.

Fanon
The ship sailed since the two are some of the main characters and spend a lot of time together. In the anime, they had two episodes just about them before another Senshi was introduced, which may have helped fuel the ship. Their dynamic compliments each other well; Usagi is the loud and carefree extrovert, while Ami is the quiet and serious introvert. Ami is always focused on studying, but Usagi helps to break it up and enables Ami to have fun and try new things.

AmiUsa is not uncommon, but there are many ships that are much more popular than it.

Fandom
FANFICTION

TUMBLR

DEVIANTART

Trivia

 * Both their Sailor names start with "M" (Moon and Mercury).
 * They are the first two Senshi to join together.

Variations

 * AmiReiUsa refers to the ship between Usagi, Ami, and Rei Hino.
 * Inner Senshi refers to the ship between Usagi, Ami, Rei Hino, Makoto Kino, and Minako Aino.