Ruby's selfishness is the entire story, not a problem to fix. Anpanman doesn't teach her a lesson so much as accidentally show her what she's been missing by being terrible. The animation moves with the kind of warmth that makes even a character's lies feel like a conversation between real people figuring things out together.
Ruby falls from the Aurora Land where she's created northern lights with her kind. Kicked out for her selfish ways, she's given one condition for redemption: find the magical Aurora Drop, a stone that grants three wishes. When she crashes into Anpanman's world, she spins a lie about needing the stone to save her homeland, and the hero believes her completely. The problem deepens when Baikinman catches wind of the wishes and starts hunting for the stone himself. Ruby finds herself genuinely bonding with Anpanman and his friends, and suddenly her original goal feels complicated. She wants to go home and earn forgiveness, but not at the cost of betraying the people who've started to trust her. As Baikinman closes in with selfish intentions, Ruby faces a real choice: grab the stone and leave, or stand with her new friends and risk losing everything she came for. It's a story about learning that sometimes the people around you matter more than getting what you thought you needed.