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