Complete the indicated task to unlock the achievement.

Achievement	How to unlock
Become a Merman	Join Minami under the sea.
Dark Grave	Cheatings dark grave.
Demon Slave	Enslaved by a Succubus.
Drinking Devil	Ruined your life over a round of drinks.
Happy End with Aiko	Beat Aiko at her own game.
Happy End with Mineko	Have a happy if easy ending.
Happy End with Rei	Tame the wild woman that is Rei.
Happy End with Yuuki	Enjoy a nice end with Yuuki.
Trio of Love	Create a perfect love triangle.
Watery Grave	Cheatings watery grave.