Final Fantasy X
Voice Actor: Paula Tiso
Lulu's first appearance sets the tone for her throughout the game, as she scolds Wakka joining them in the Chamber of the Fayth. After she notices that Tidus is with him, the situation gets even worse for Wakka as she berates him more.
Shortly after, Wakka and Lulu talk outside Tidus' tent about Chappu and how Tidus isn't a replacement for him. Lulu doesn't seem to be very accepting of Tidus' presence with the group and isn't keen on him joining them on their trip. This continues as they prepare to leave Kilika for Luca, as Lulu is concerned that Tidus might not find anyone he knows.
You Don't Want To Finish That Sentence
After helping Tidus and Kimahri rescue Yuna from the Al Bhed, they watch Wakka playing in the Blitzball game. Lulu originally comments that Wakka won't be able to see the game out, but when he does, she still has very little positive to say.
She suggests that had Chappu been playing, he would have won and still been standing afterwards. Tidus tries to step in, but Lulu highlights a sensitive area by telling Tidus that he doesn't want to finish his sentence.
Shortly after, Lulu informs Tidus of why Wakka hates the Al Bhed. Instead of using the sword Wakka gave him, he left to fight for the Crusaders using Al Bhed weaponry and was killed.
An Experienced Guardian
Despite her young age, Lulu is still an experienced Guardian as prior to guiding Yuna through her pilgrimage, she had been the Guardian to two other Summoners. Unfortunately, neither of them made it to Zanarkand, as Lady Ginnem was killed while attempting to acquire Yojimbo, and Father Zuke decided to quit his pilgrimage when they reached the Calm Lands.
Lulu was also romantically involved with Chappu prior to his death and it is these experiences that helped to shape the type of indivdual Lulu is, and explains why she is both very protective of Yuna and why she has an odd relationship with Wakka.
Upon finding out that there is no Final Aeon, Lulu is the first person to volunteer her life so that Yuna can complete her pilgrimage. However, when Yuna decides to question Yunalesca about Sin, interesting information is disclosed.
Yunalesca informs them that Sin will always return, which shocks Lulu. The teachings stated that if the citizens of Spira atoned for their sins, that Sin would be exorcised. However, Yunalesca tells her that the teachings only give people hope, they aren't necessarily true.
Final Fantasy X-2
Voice Actor: Paula Tiso
Shortly after the end of Final Fantasy X, Wakka and Lulu realise they have feelings for each other and settle their differences. This culminates in the couple getting married and Lulu becoming pregnant with Wakka's child.
During the game, Lulu actually gives birth to the child and Wakka names the baby boy Vidina.