Kumi Shachou no Hatsujou wa Gonaimitsu ni.

Kumi Kazumasa is the second son of an alpha family who is not only an excellent and handsome man, he also has various high-degree capabilities that make him the envy of others. While he has gained attention as a young hopeful, he has been so immersed in work that he hasn't had a lover in years. Plus, it's even harder to find new love since his secretary, Jinya Satoru has not only been managing his work, but has also been making sure that Kazumasa always takes his supplements after meals. But one day, after taking a sample nutritional drink, a sudden change occurred in Kazumasa's body!

(Source: Kadokawa, translated)