He's the chief at Sawamura Minori's company. He picks Minori for his team; however, he has his eyes on her and investigates her relationship with Hatsuhi.
Saiga Umetaro is created by Chihiro Harumi, and he has no information regarding any inspiration used to create him. Saiga first appears in chapter 7 of Koi o Suru no ga Shigoto Desu volume 1.
His usual attire is a business suit and tie.
He is a womanizer and uses his wealth and status to sleep with several co-workers.