Here is the full list of all 9 Last Days of Spring Visual Novel achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Completed all endings.
Completed Yuri ending.
Completed friendship ending.
Completed Michiko ending.
Completed Keisuke ending.
Completed Takeo ending.
Chose to let Saori have Takeo to herself.
Walked to school.
Took car to school.