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.
Find all hidden caves in Hana Gakuen.
Kill Lady Chiyo with any character other than Aiko.
Fail the Shrine riddle at the beginning 3 times.
Listen to everything Kuma has to say.
Don't extinguish any light sources in Matsuyama.
Don't kill anyone with Takuma during the mission “The Best Laid Plans.”
Collect 17 badges.
Kill or knock out 5 guards at the same time with all 5 characters.
Talk to a samurai when disguised with Aiko.
Kill the Captain.
Kill 10 guards with Takuma's Sniper Rifle that are farther than 25 meters away from him.
Kill a Samurai with a flower pot.
Find the perfect spot for sunbathing.
Kill all enemies at the mansion in Nagoya.
Distract 50 guards with Hayato's stone.
Come out of the other side of the river in Nagoya.
Finish all missions.
Finish “The Secrets of Hana Gakuen”.
Use Aiko's disguise 15 times.
Kill a samurai with a rock.
Kill 10 guards with a drop attack.
Kill 30 guards with the help of the environment.
Kill 10 guards with traps in Hana Gakuen.
Hide with all characters in a single bush.
Hide 150 bodies.
Kill at least 3 guards in the mission “A Night at Sea”.
Finish the mission “Red Lights at Matsuyama”.
Finish the mission “The Best Laid Plans”.
Kill 3 Samurai with Yuki.
Execute a plan with all 5 characters.
Kill or knock out 150 guards.
Travel 1200 meters in water during the mission “The Best Laid Plans”.
Hide 100 bodies.
Kill or knock out 100 guards.
Finish the mission “A Night at Sea”
Distract 4 guards at the same time with Kuma.
Finish the mission “Reunion at Nagoya”.
Kill 20 guards with Mugen's Swordwind.
Hide 50 bodies.
Kill or knock out 50 guards.
3 times in one mission, kill 2 guards at once with Mugen's Swordwind.
Kill a guard with a drop attack from a rope.
Throw a guard into a well.