The Busy Bee Falls for the Useless Cat's Meow

Junya Hisayoshi's a businessman who has a lot of certifications. Upon orders from his father, who runs a temp staffing firm, he goes undercover into one of his client's rival companies. The target is their current president, Zen Asahina, who is devilishly handsome and a former model, and there are many rumors about his business methods. Based on information that Zen once dated a guy, Junya tries to seduce Zen while they're alone in his office, but he's causally turned down and made to endure humiliation. However, Junya then finds out about Zen's super-kept secret...?