Here is the full list of all 22 Sword of Asumi achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Completed Hikari's Unrequited Love Ending
Killed Utsuro at the End
Completed the 'canon' ending to the game
Completed the Dying Alone Ending
Completed Mercy is for the Weak Ending
Saved the World and fell in love #1
Saved the World and fell in love #4
Saved the World and fell in love #2
Saved the World and fell in love #3
Suggest to Kaori she is your type too
Assassinate the kidnappers after they talk
Drug the Principal for Information
Came first on the Obstacle Course
Killed Mineko at the End
Get a perfect score in Tactics with Sen
Impress Kami with your poetry skills
You Spread Rumours about Hiro & Jiro
Skipped the intro on second playthrough
Kill Everyone in the intro
Completed the entire game at least once
Completed Death of Hikari Ending
Try a little cosplay with Kaori