Here is the full list of all 6 A summer promise to forever achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
I CAN NOT PROTECT YOU
你竟然下了HS补丁
HAVE A NORMAL ENDING
HAVE A GOOD ENDING WITH WUWANXUE
HAVE A GOOD ENDING WITH XUYUETING
OPEN THE GAME FIRST TIME