Here is the full list of all 26 Pixel Puzzles: Japan achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Enlightenment Attained
Consciousness Raised
A Mind In Training
On The Road To Enlightenment
All Puzzles Complete!
Tsukubai
Gardens of Nijo Palace
Akai Hashi
Himeji Castle Gatehouse
Cherry Blossom Over Water
Butsudan
Hiroshima Castle Gatehouse
Temple Lanterns
Komainu No Enryakuji
Nara Temple Gates
Iwakuni Bridge
Koen
Osaka Castle
Stop The Pop... With A FIsh
Himeji Castle
Urabandai Lakes
Torii
Red Temple Of Nara
Komainu No Osaka
Zen Garden
Pull It OUT!