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.
Finish all missions.
Listen to everything Kuma has to say.
Finish “The Secrets of Hana Gakuen”.
Kill Lady Chiyo without getting a disguise.
Kill Lady Chiyo with any character other than Aiko.
Hide 150 bodies.
Kill or knock out 5 guards at the same time with all 5 characters.
Execute a plan with all 5 characters.
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.
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.”
Kill the Captain.
Kill 10 guards with Takuma's Sniper Rifle that are farther than 25 meters away from him.
Kill a Samurai with a flower pot.
Travel 1200 meters in water during the mission “The Best Laid Plans”.
Hide 100 bodies.
Distract 50 guards with Hayato's stone.
Find the perfect spot for sunbathing.
Kill or knock out 150 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 all enemies at the mansion in Nagoya.
Finish the mission “Reunion at Nagoya”.
Kill 3 Samurai with Yuki.
Kill 20 guards with Mugen's Swordwind.
Use Aiko's disguise 15 times.
Kill or knock out 100 guards.
Hide 50 bodies.
Come out of the other side of the river in Nagoya.
Kill 10 guards with a drop attack.
Kill or knock out 50 guards.
Talk to a samurai when disguised with Aiko.
Kill a samurai with a rock.
3 times in one mission, kill 2 guards at once with Mugen's Swordwind.
Kill a guard with a drop attack from a rope.
Throw a guard into a well.
Collect 17 badges.