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