Here is the full list of all 49 Yokai's Secret achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Yokai's Secret
Get all colors back
Draculea's Secret
Get all stars from Draculea
Meet Draculea
Kinutanuki's Secret
Get all stars from Kinutanuki
Use a hint in game
Meet Kinutanuki
Amanozako's Secret
Get all stars from Amanozako
Meet Amanozako
Kawauso's Secret
Get all stars from Kawauso
Meet Kawauso
Akakami's Secret
Get all stars from Akakami
Meet Akakami
Get all stars from Kurage
Kurage's Secret
Meet Kuragenohinotama
Kinoko's Secret
Get all stars from Kinoko
Meet Kinoko
Ouni's Secret
Get all stars from Ouni
Meet Ouni
Get all stars from Ungaikyu
Neko's Magic
Ungaikyu's Secret
Meet Ungaikyu
Meet Ichiko
Ichiko's Secret
Get all stars from Ichiko
Kuda's Secret
Get all stars from Kudagitsune
Meet Kudagitsune
Atake's Secret
Get all stars from Atake
Meet Atakemaru
The Story
Meet Neko
Neko's Secret
Get all stars from Neko
Meet Kanedama
Kane's Secret
Get all stars from Kane
Open the friend book(please install free DLC)
Yokai's Encounter