WARNING: The following contains major spoilers for Season 1, Episode 12 of Lapis Re:LIGHTs, "Specificity Ornament," now streaming on Crunchyroll.
Flora Girls' Academy is in trouble by the end of Lapis Re:LIGHTs. Luckily, Tiara and her friends selflessly step up to the plate and finally earn a just reward. The drama kicks off when the city in which their school resides in is threatened by a wave of magical monsters -- the likes of which can only be repelled by brave citizens maintaining defensive lines -- as well as the reservoir of magic that the city typically replenishes -- with their various Orchestras. While the Orchestras of this city aren't directly fighting on the front lines, Tiara and her group's contribution is crucial in saving what they love.
The director of Flora Girls' Academy, who, at one point, was in one of the most popular Orchestras around, has a plan for the city. At the time that these monsters are expected to arrive, the students of the Academy, which form Orchestras, are expected to give it their all under the guise of a large festival. Of course, the students are a bit nervous about it, but they ultimately steel themselves for the task at hand.
This final episode does an interesting job when it comes to these performances, attaching the end of one to the beginning of another with a melody that somewhat connects to the other performances in sequence. Despite the girls' best efforts, it appears that they don't accrue quite enough mana to save the city. While they sing, there are unnamed soldiers who get battered by the monsters outside, adding extra tension to this realization. If they were on their own, then more desperate measures would need to be taken.
However, moments after this happens, LiGHTs (Tiara's group) grabs everybody's attention. Dropping down from their ship in the sky, Tiara and company float high above the city and proceed to perform in a manner quite like their first attempt. The only difference between these performances is the relative stakes, with this song being crucial to the city's survival. They don't have any expectations of reward going into this performance, just the motivation to help the friends that they made at the Academy.
With this performance, the city collects just enough magic to activate a spell that wipes out all of the monsters. Tiara and her friends then get a touching reunion with the members of the other Orchestras that they met at the academy. While the performance is tiring for them, the other girls agree on the fact that Tiara's group was a great performance.
Their actions also set a precedence for how Tiara's relationship with her sister is going to function from now on. While Tiara notes in this episode that her sister was always protecting her, the princess now wants to have the opportunity to protect her older sister. Considering that Tiara's older sister was part of an Orchestra that was idolized for its achievements, this action serves as a sort of "passing on the torch" from sister to sister.
The post-credits scene for Season 1 adds the perfect finishing touch. Throughout the majority of the Lapis Re:LIGHTs, Tiara and her friends have been struggling to maintain their status at the school. However, after their valiant efforts in defense of the city, the girls are rewarded by the very school they were expelled from. Since they are wearing uniforms that are different from the standard Lapis outfit, this means that not only are the girls out of the bottom tier but they also secured for themselves an even better rank. With such an ending, it's safe to say that LiGHTs' dream of continuing to perform isn't going to fade anytime soon.