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