Tsukuru and colorless

Five high school friends, inseparable. Coincidentally, their names all refer to a color. The first is Akamatsu (meaning red pine), the second is Omi (meaning: blue sea), the third is Shiran (meaning: white root), and the fourth is Corona (meaning: black field). Only Sukuro Tazaki has no color in his name.
Suddenly, these friends decide to cut ties with Tsukuru and Tazaki forever. This is how Socorro wanders through his life, carrying a burden he doesn't know, and he can't even make close friends again.
However, after many years, he meets someone who heals that old wound and urges him to discover the reason and what happened in those lost years.