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