Rui is a purple haired dude with blue strands on his hair,yellow eyes and a cat-like grin,he likes to invent little robots or gadgets since he's very creative. He is sly and teasing mostly silly all the time yet also caring and sweet,his biggest love is tsukasa Tenma,his lovely boyfriend since high school and Rui is sure that tsukasa is an angel sent from above,they love each other so much and Rui would die in order to keep tsukasa safe and happy