Motoharu Toriumi

Mink's manager and Mohako's older brother. Mahoko and him were separated when their parents got divorced: Mahoko going with their mum and him with their dad. He cares a lot about Mink's well being, putting her above any value of money, but it is unknown if he returns her feelings or whether he is even aware of them. He is unaware of Mink's true identity and later becomes Yuka's manager. (Wikipedia) He is called Sempai by Mink, Mo-kun by his dad and Onii-chan by his sister.