Here is the full list of all 33 Mitsurugi Kamui Hikae achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Complete all upgrades
Clear Inferno difficulty
Collect 100,000 SP
Clear Very Hard difficulty
Clear Normal difficulty
Clear Easy difficulty
Defeat 1000 enemies
Perform 10 Flourishes
Perform a Counter
Perform 10 Counters
Clear Hard difficulty
Defeat stage 5 boss "Magatsu Suzuka" (any difficulty)
Defeat stage 6 boss "Magatsu Hino Tsurugi" (any difficulty)
Defeat stage 4 boss "Magatsu Kaina" (any difficulty)
Max out Katana Gauge
Defeat stage 3 boss "Suzuka" (any difficulty)
Perform a Flourish
Defeat stage 2 boss "Kaiser" (any difficulty)
Max out Life Gauge
Watch the tutorial
Defeat stage 1 boss "Kaina" (any difficulty)
Defeat 10 enemies
Defeat 100 enemies
Use Zanshin to defeat an enemy
Use Zanshin to defeat 50 enemies
Use Zanshin to defeat 100 enemies
String 50 hits
String 100 hits
Perform the holy technique "Celestial Judgement"
Perform the holy technique "Divine Wind"
Perform 10 Just Guards
Reach "Mitsurugi" zeal level
Perform a Just Guard