What Color Is Summer?

The story always seems to take place in the summer. Four guys with very different personalities embarked on an adventure in the summer, but announced they were breaking up in the fall. The smartest one chose to leave without saying goodbye. The weirdest one chose to go far away. The most astute one chose to remain silent. The most unscrupulous person chose to get seriously ill. The pain of growing up is always as painful as skin cramps, and reunion is always hidden at every ordinary corner. What changes will happen in the new adventure?