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A confident succubus and a man with a bad erection

Meri, a succubus apprentice, descends into the human world for her graduation exam.
Meri aims to pass the exam in first place, but Masayuki, who was chosen in a lottery, turns out to be a super lethargic person (and has an ED)!
She will make this man cum with her pride!

English Webtoon version: https://comiko.net/series/94046/the-succubus-is-confident-but-her-target-is-impotent