In the plot of this novel, the protagonist raised a younger sister. Was there a plot where he would give whatever his younger sister wanted? Also, did his sister want a house made entirely of crystals?

I recommend "Familiar: Sister's Death, I Evolve". The main character has a younger sister. The younger sister wishes to have a house made of crystal, so the main character helps her build one. Other than that, this novel has more interesting plots. Come and take a look! I hope you like my recommendation. Muah ~