Here is the full list of all 44 Shadow Tactics: Blades of the Shogun - there are Aiko's Choice achievements.
Kill Lady Chiyo without getting a disguise.
Find all hidden caves in Hana Gakuen.
Kill Lady Chiyo with any character other than Aiko.
Finish all missions.
Listen to everything Kuma has to say.
Finish “The Secrets of Hana Gakuen”.
Collect 17 badges.
Kill a samurai with a rock.
Talk to a samurai when disguised with Aiko.
Kill 10 guards with traps in Hana Gakuen.
Find the perfect spot for sunbathing.
Kill the Captain.
Execute a plan with all 5 characters.
Kill or knock out 5 guards at the same time with all 5 characters.
Kill 10 guards with Takuma's Sniper Rifle that are farther than 25 meters away from him.
Distract 50 guards with Hayato's stone.
Kill a Samurai with a flower pot.
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.
Finish the mission “The Best Laid Plans”.
Don't kill anyone with Takuma during the mission “The Best Laid Plans.”
Hide 150 bodies.
Kill 3 Samurai with Yuki.
Travel 1200 meters in water during the mission “The Best Laid Plans”.
Hide 100 bodies.
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.
Use Aiko's disguise 15 times.
Kill all enemies at the mansion in Nagoya.
Finish the mission “Reunion at Nagoya”.
Kill 30 guards with the help of the environment.
Come out of the other side of the river in Nagoya.
Kill or knock out 150 guards.
Hide 50 bodies.
Kill 10 guards with a drop attack.
Kill or knock out 100 guards.
3 times in one mission, kill 2 guards at once with Mugen's Swordwind.
Kill or knock out 50 guards.
Kill 20 guards with Mugen's Swordwind.
Kill a guard with a drop attack from a rope.
Throw a guard into a well.