I found this book delightful and would recommend it. You can find it here in english.
Here's a story with intellectual texture. It's created from the inner worlds of two thoughtful narrators: the super-smart 12 ½ year old Paloma Josse and the guarded 54-year-old Renee Michel. They live in a luxury building in central Paris where the wealthy residents are arrogant and self-satisfied.
Renee and Paloma are the exceptions. Renee is the building's concierge. She describes herself as a short, ugly and plump widow who is poor, discreet and insignificant. But Renee is much more than she appears. She deliberately hides her intelligence, believing it is wrong for her to be smart. And so the TV set drones in the front room of her lobby apartment, giving the impression to passing residents she's sprawled in front of it, as they would expect. But in reality, Renee is in a back room engaged in her love of the arts. She is a prophet of the contemporary elite, more enlightened than the residents she serves.
Except for Paloma, who is a wise, old soul in a child's body burdened by the meaninglessness of her world. She, like Renee, lives within the padded walls of her lonely gifted mind, suppressing her talents at school and at home. Paloma lives on the 5th floor and she disdains her high-brow parents and sister. Convinced life is a farce, Paloma decides to commit suicide on her 13th birthday. She also decides to keep a journal of profound thoughts and beautiful things in the months approaching that day to be sure suicide is the right decision. Paloma is a rebel of social norms.
The plot is simple, unfolding with little action or embellishment as it portrays the transformation of Renee and Paloma when a Japanese gentleman purchases an apartment in their building. His recognition of their gifted minds creates a turning point in their lives and brings together these kindred souls.