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