Here is the full list of all 15 Dungeon Bar: Gachi Puzzles achievements.
Perfect
Boss of this Gym
"Give me your Password..."
Master of the Dungeon
Mr. Flexx
"...three hundred bucks"
"Ahhhh..."
"Give me a cola"
"Brother"
"Kawaii"
"Legendary Battle"
"Sorry for what?"
???
"Good night sweet prince"