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.”
Find the perfect spot for sunbathing.
Come out of the other side of the river in Nagoya.
Find all hidden caves in Hana Gakuen.
Listen to everything Kuma has to say.
Talk to a samurai when disguised with Aiko.
Use Aiko's disguise 15 times.
Collect 17 badges.
Kill 10 guards with Takuma's Sniper Rifle that are farther than 25 meters away from him.
Don't extinguish any light sources in Matsuyama.
Kill Lady Chiyo with any character other than Aiko.
Finish all missions.
Finish “The Secrets of Hana Gakuen”.
Kill a samurai with a rock.
Kill Lady Chiyo without getting a disguise.
Kill 3 Samurai with Yuki.
Kill 30 guards with the help of the environment.
Kill 10 guards with traps in Hana Gakuen.
Kill or knock out 5 guards at the same time with all 5 characters.
Execute a plan with all 5 characters.
Hide with all characters in a single bush.
Fail the Shrine riddle at the beginning 3 times.
Finish the mission “Red Lights at Matsuyama”.
Kill 10 guards with a drop attack.
Finish the mission “The Best Laid Plans”.
Travel 1200 meters in water during the mission “The Best Laid Plans”.
Kill the Captain.
Hide 150 bodies.
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.
Finish the mission “Reunion at Nagoya”.
Kill all enemies at the mansion in Nagoya.
Hide 100 bodies.
Kill or knock out 150 guards.
Kill or knock out 100 guards.
Hide 50 bodies.
Kill a Samurai with a flower pot.
Kill or knock out 50 guards.
Kill 20 guards with Mugen's Swordwind.
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.