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