The Wallflower manga books 1-3 Yamatonadeshiko Shichihenge

MAKEOVER OF THE CENTURY It's a gorgeous, spacious mansion, and four handsome, fifteen-year-old friends are allowed to live in it for free! There's only one condition--that within three years the guys must transform the owner's wallflower niece into a lady befitting the palace in which they all live! How hard can it be?