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.
A Mind In Training
All Puzzles Complete!
Tsukubai
Enlightenment Attained
Gardens of Nijo Palace
Himeji Castle Gatehouse
Akai Hashi
Butsudan
Consciousness Raised
Hiroshima Castle Gatehouse
Temple Lanterns
Cherry Blossom Over Water
Koen
Nara Temple Gates
Iwakuni Bridge
Komainu No Enryakuji
Osaka Castle
Zen Garden
On The Road To Enlightenment
Komainu No Osaka
Red Temple Of Nara
Himeji Castle
Urabandai Lakes
Stop The Pop... With A FIsh
Torii
Pull It OUT!