Final Fantasy X
Voice Actor: Tara Strong
Rikku initially comes to the aid of Tidus as he is trying to fight off a fiend. However, following its defeat her compatriats attempt to kill Tidus as well. Fortunately she is able to convince them that Tidus should be taken captive instead, and he is taken to the Al Bhed boat to work for them.
Shortly afterwards, she speaks to Tidus about how he ended up there and she seems confused when he claims to be from Zanarkand. However, before they can learn more about each other, Tidus is swept overboard.
You Big Meanie!
Rikku re-appears outside the Moonflow having been defeated by Wakka and Tidus when she attempted to kidnap Yuna. She gets swept up on the shore and after she initially calls Tidus a big meanie for beating her, she then engages in conversation with Lulu and Yuna.
They both decide that Rikku should become Yuna's Guardian too and after Auron says it's ok, it is confirmed. However, for all her usefulness at opening chests and boosting morale, she doesn't have much courage when facing her biggest fear.
Arriving At The Thunder Plains
After leaving Guadosalam, the group's next stop was the Thunder Plains. It is here that we find out about Rikku's crippling fear of Lightning. She tries to convince them to wait a while to see if it will subside, but Auron makes them push on.
He does relent though and lets them rest in the Travel Agency which is in the middle of the Thunder Plains. However, when they have to move on again Rikku manages to eventually conquer her demons and they make it to Macalania successfully.
Rikku Should Stay Rikku
Upon exiting the Macalania Woods, Yuna is greeted by Tromell Guado. He requests that he be allowed to take Yuna on his own to meet Maester Seymour Guado, a request which is granted. However, they are shortly attacked by Al Bhed led by Brother.
When Wakka finds out that Rikku is Al Bhed he is beside himself with anger. Rikku tries to defend herself, but Wakka storms off in disgust. Lulu is able to comfort Rikku and convince her that she's done nothing wrong. However, when they're at the bottom of Lake Macalania, Rikku claims she wishes she were more like Yuna; being able to keep calm. This prompts Kimahri to say that Rikku should stay Rikku.
Following their arrival at Bikanel Island and the eventual destruction of Home, Wakka tries to apologise by making a badly timed joke. Rikku effectively tells him where to shove it, but following this incident their relationship is more tolerant.
We've Got To Save Yunie!
Rikku believes that in Tidus, she has found an ally in her quest to save Yuna. Although she doesn't exactly know how, she knows there must be a way to defeat Sin without the Summoner losing their life and she gives Tidus the responsibility of figuring that out.
As they approach Zanarkand, she tries to stall as much as possible, but eventually the answer presents itself naturally when they speak to Lady Yunalesca, as afterwards Rikku realises that the Hymn of the Fayth makes Sin docile.
Final Fantasy X-2
Voice Actor: Tara Strong
After Sin was defeated, both Rikku and Brother fell out with Cid. Following this, they formed the Gullwings, along with Buddy and Shinra. Paine soon joined them shortly after and they began searching for Spheres across Spira. It was because of this that Kimahri gave them a Sphere he found on Mt. Gagazet which featured a young man who looked similar to Tidus.
After this discovery, Rikku quickly rushed to Besaid Island where she showed it to Yuna. Yuna then joined the Gullwings the three of them started travelling the globe trying to find more Spheres about this mysterious person.
For the most part, Rikku plays a relatively minor role in the story. Having said that, there are a few hints that she had a relationship with Gippal in the past. This is never really elaborated on though.