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