Kimekoi! Takane no Hana to Osananajimi ga Kimatta Riyuu

Just one single pill and also you can't stop!! It's a drug that assists people realize their soul mates. This aphrodisiac unites a "beauty highInch with her childhood friend, and passionate sex ensues! Mukaiyama Hajime falls hopelessly crazy about a student rumored is the most breathtaking in school, Saginomiya Megumi. He plans to confess the romance to her but worries that she's away from his league. He asks his friend Misa for advice.

Misa, president in the science club, develops "KimeKoi", a medication meant to amplify any preexisting feelings of love inside user. But a sample of Hajime's semen is needed to result in the drug. Hajime watches, bewildered, as Misa starts unzipping Hjime's pants...