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