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