Just finished Land of the Lustrous anime and thought it was amazing. Only disappointed there wasn’t more, I don’t like to read manga so if someone would just comment some good spoilers.
I respect your choice entirely, but do reconsider reading the manga. Its good enough to be recognised as the 17th best Manga of all time. Absolutely genius in almost all aspects.
Since for me it's one of the best stories i've ever heard/watched/read I would recommend hard just to read the manga once u've finished anime.
But if u don't wanna go that way,
few things happens like meeting a gem called Ghost Quartz that i'ts like double personality gem, cause phos mistepped in a fight one of their personalities ends getting killed (sort of) and now that gem really hates her, later in a fight phos loses her head (literally) and they tried to implant her one of an old gem called Lapislazuli, timeskip 200 years the body tolerates Lapislazuli's head and now Phos is like really clever and more manipulative.
She plans to travel to the moon and ends up doing it alone, phos starts attacking but at the end she founds the moon leader called Aechmea and becomes an infodump session. Looks like the moon it shines cause its done of the gems they take from the earth and they transform into gem dust, this is an attempt of moon people to make sensei ''pray for them''.
Sensei its an old machine that was made by humans thousands of years ago, and he was made to set free from the suffering of souls people by praying, moon people are souls that got trapped in the world and cannot leave in peace nor die. Well, Phos understands that if they make Sensei pray they will stop the moon people attacks bc they will die, so she joins the moon people.
She comes back earth, convinces a bunch of gems to go to the moon, some others disagree and end up teaming with sensei and kinda becoming new moon gems enemies, phos by herself tries to go back to earth and make sensei pray, the other gems attack phos and they spread phos fragments all around the isle.
250 years later (i think) they completely forgot about Phos, so in winter sensei stays awake and rearms phos, she tries to sensei pray for her, looks like sensei is a broken machine and if he prays, instead of only setting free the souls (moon people) he sets everyone free so also gems and those ocean things die, and sensei fell in love with gems so he is completely unable to do it by himself.
Nothing happens, moon gems rescue Phos, filled with revenge cause the other gems attacked her 250 years ago when she was acting peacefully, she plans to attack with everyone (moon gems and moon people included) to kill all gems in earth and force for one and all sensei's praying.
They go to earth and start the fight. Dia vs Bort, Phos vs Cinnabar, alexandrite one man army, they destroy everyone but Phos ends up kinda fked cause cinnabar's mercury, she finds sensei, she says really ugly things to him and like he's unable to pray, ends up giving her the possibility to pray (looks like his power to pray was held in his eye), sensei dissapears, phos puts sensei's eye.
Plot twist, looks like in order to complete the praying its needed to wait 10000 years, so everyone dissapears, they are like together in the afterworld (moon people and gems), phos is alone in the world and watching through sensei's eye what he suffered since he existed, so now Phos gonna suffer alone 10000 years horrendous things.
I skipped lots of things but I personally think it's a great summary xd
