Koukishin wa Naniiro ni Kagayaku?

[Serious and reliable 27 years old man X Fluffy airheaded 35 years old man] Sayama, who works at a Pharmaceutical Manufacture Company decided to give a prototype energy drink to Iruma, the man who has been exhausted day after day from overwork. It transformed the drained and tattered Iruma into an energetic beauty but Sayama was suddenly invited to 'have sex' and is about to be attacked?! There's a mysterious side effect from the energy drink...?! "Let's have sex."