Here is the full list of all 23 BUNNY GARDEN achievements.
Made a Cast Drunk
Went to a Swimsuit Event
Invited to Rin's Birthday
First Time at Afters
Played Hand Sumo
Played T Game
Took a Photo
Max Zoomed while Making a Drink
First Time at the Shop
Traveled with Kana
Traveled with Rin
Traveled with Miuka
Invited to Kana's Birthday
Invited to Miuka's Birthday
Bought Kana's Champagne
Bought Rin's Champagne
Bought Miuka's Champagne
Gifted All the Panties
Gifted Pantyhose to All Cast
Watched Kana's Happy Ending
Watched Rin's Happy Ending
Watched Miuka's Happy Ending
Watched Harem Happy Ending