Rei Hino will be the death of me. These scenes with her will just NOT STOP COMING.
So, Ami suggests that Rei try out the Sailor V game, but Rei is a bit apprehensive because she’s never played a video game before. Ami coaches Rei through the game, allowing her to beat it. Overcome with excitement, Rei high-fives Ami.
However, she then gets self-conscious. Remember, this is a girl who has spent the majority of her life with no one to depend on or spend time with except for her grandfather and Phobos and Deimos, her two crows. So of course she’s self-conscious about one of her first outings with her new friends. Of course she’s probably worrying about what to do and say in this completely alien situation; who wouldn’t be?
But once she goes with her feelings, she finds that everything will be alright. Being with Usagi and Ami is just so easy, she doesn’t have to worry about keeping up the front of an aloof and mysterious lady. She can do and say whatever she wants and these girls will still stand by her.
That “thanks, Ami-chan!” probably has to do with a lot more than just beating the game.