Here is the full list of all 21 Riddle Joker achievements.
Start a new game
Start Ayase's Route
Clear Ayase's Route
Start Nanami's Route
Clear Nanami's Route
Start Mayu's Route
Clear Mayu's Route
Start Hazuki's Route
Clear Hazuki's Route
Start Chisaki's Route
Clear Chisaki's Route
Nanami hanging onto the rope
Save Hazuki from harm
Have a serious discussion about a certain topic with Ayase
Hazuki is getting hit as an innocent bystander
Listen to Ayase talking about cats
Ayase losing playing cards
Aren't you curious about Mayu's browser history?
Watch Hazuki's "performance"
Just a normal ending
Clear all Achievements