Here is the full list of all 44 Shadow Tactics: Blades of the Shogun - there are Aiko's Choice achievements.
Find all hidden caves in Hana Gakuen.
Find the perfect spot for sunbathing.
Come out of the other side of the river in Nagoya.
Listen to everything Kuma has to say.
Kill Lady Chiyo with any character other than Aiko.
Talk to a samurai when disguised with Aiko.
Fail the Shrine riddle at the beginning 3 times.
Distract 4 guards at the same time with Kuma.
Kill at least 3 guards in the mission “A Night at Sea”.
Don't kill anyone with Takuma during the mission “The Best Laid Plans.”
Execute a plan with all 5 characters.
Kill or knock out 5 guards at the same time with all 5 characters.
Kill Lady Chiyo without getting a disguise.
Kill a samurai with a rock.
Don't extinguish any light sources in Matsuyama.
Kill a Samurai with a flower pot.
Collect 17 badges.
Kill 3 Samurai with Yuki.
Kill 10 guards with Takuma's Sniper Rifle that are farther than 25 meters away from him.
Finish all missions.
Finish “The Secrets of Hana Gakuen”.
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 30 guards with the help of the environment.
Travel 1200 meters in water during the mission “The Best Laid Plans”.
Hide 150 bodies.
Kill 20 guards with Mugen's Swordwind.
Kill the Captain.
Finish the mission “A Night at Sea”
Kill all enemies at the mansion in Nagoya.
Finish the mission “Reunion at Nagoya”.
Kill or knock out 150 guards.
Distract 50 guards with Hayato's stone.
Hide 100 bodies.
Kill 10 guards with a drop attack.
Use Aiko's disguise 15 times.
Kill or knock out 100 guards.
Kill a guard with a drop attack from a rope.
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.