Here is the full list of all 44 Shadow Tactics: Blades of the Shogun - there are Aiko's Choice achievements.
Kill Lady Chiyo without getting a disguise.
Kill a samurai with a rock.
Kill or knock out 5 guards at the same time with all 5 characters.
Find all hidden caves in Hana Gakuen.
Kill Lady Chiyo with any character other than Aiko.
Execute a plan with all 5 characters.
Collect 17 badges.
Kill 3 Samurai with Yuki.
Kill all enemies at the mansion in Nagoya.
Come out of the other side of the river in Nagoya.
Talk to a samurai when disguised with Aiko.
Fail the Shrine riddle at the beginning 3 times.
Listen to everything Kuma has to say.
Hide 150 bodies.
Kill at least 3 guards in the mission “A Night at Sea”.
Kill 30 guards with the help of the environment.
Finish all missions.
Finish “The Secrets of Hana Gakuen”.
Use Aiko's disguise 15 times.
Kill 10 guards with a drop attack.
Hide 100 bodies.
Kill 10 guards with traps in Hana Gakuen.
Kill 20 guards with Mugen's Swordwind.
Hide with all characters in a single bush.
Finish the mission “Red Lights at Matsuyama”.
Don't extinguish any light sources in Matsuyama.
Kill 10 guards with Takuma's Sniper Rifle that are farther than 25 meters away from him.
Finish the mission “The Best Laid Plans”.
Don't kill anyone with Takuma during the mission “The Best Laid Plans.”
Kill the Captain.
Distract 4 guards at the same time with Kuma.
Distract 50 guards with Hayato's stone.
Find the perfect spot for sunbathing.
Kill a Samurai with a flower pot.
Travel 1200 meters in water during the mission “The Best Laid Plans”.
Kill or knock out 150 guards.
Hide 50 bodies.
Kill or knock out 100 guards.
Finish the mission “A Night at Sea”
Finish the mission “Reunion at Nagoya”.
3 times in one mission, kill 2 guards at once with Mugen's Swordwind.
Kill or knock out 50 guards.
Kill a guard with a drop attack from a rope.
Throw a guard into a well.