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