Succubus-san is Inquisitive

Succubus-san is Inquisitive "Sakyubasu-san wa Ibukashige" (サキュバスさんはいぶかしげ) is the seventh episode of Demi-chan wa kataritai.

Synopsis
As she's walking through the school building, Sakie spots a beautiful blond-haired boy sitting on the floor, crying and hugging his knees. He says his name is Kurtz and doesn't seem to be a student of Shibasaki High, behaving a bit suspiciously. Meanwhile, Hikari says she's just seen another suspicious individual in the school, describing him as a large man who looked like a bear...undefined

Trivia

 * Succubi are revealed to only affect straight men with their aphrodisiac effect.
 * Kurtz is clearly gay, as Satou had no effect on him.
 * Though this still leaves the question if gay women are affected by Succubi.