Sakuya Aima

Sakuya Aima or Leviathan is one of the characters featured in Succubus Heroines Eroge.

Pre-Transformation
A classmate of the main character and Asuna.

She has a quiet personality, and is extremely timid, so much so that she can't even have a conversation with someone she just met for the first time.

For that reason, her classmates often make fun of her. She has fallen deeply in love with the main character, but due to her timid nature, she can't even talk to him, let alone tell him how she feels.

Leviathan
Sakuya, after having become a succubus.

The second victim of a succubus who came from the Demon Realm. When it happened, she was thoroughly educated, and as a succubus, her power is vast.

Perhaps as a reaction because of her long repression, she is extremely aggressive and confident compared with Sakuya. She has gotten the students of Nishizumi High to obey her, one after another. The boys were entranced by her beauty, and she converted the girls into succubi. She's started acting just like a queen.

She harbors great animosity and jealousy towards Asuna, who is always at the main character's side. She attacks the main character in attempts to make him into her very own personal slave.

Also, she absolutely adores the succubus who initiated her transformation.