SILK-1952 been too long - Leila Fujii

One day, Naota and Anna meet by chance for the first time in 15 years. They were each other's first boyfriend and girlfriend, but their relationship faded away due to Naota's busy schedule and their separate entrance exams. They openly admit to each other that they never hated each other, and their love is rekindled, leading to a relationship. However, for some reason, as adults, the two become intimidated, and their relationship never progresses...!