Keiichiro is the manager and baker of Cafe Mew Mew and Ryouss partner in the Mew Project.
Five years before the start of Tokyo Mew Mew, Keiichiro worked with Dr. Shirogane, Ryou's father, on the Mew Project in the United States. After Ryou's parents were killed in a lab explosion, Keiichiro went with Ryou to Japan to continue working on the Mew Project. Keiichiro cares a great deal for Ryou, and worries when he risks himself to help the Mew Mews. Knowing he couldn't stop Ryou, though, he only makes him promise to return because he'll be waiting with tea to welcome him home.
He is shown to have a mischievous and flirtatious side, however, such as offering to kiss Ichigo to change her out of her cat form. Ichigo once wondered if Keiichiro might be the Blue Knight after she sees he has an injury in the same spot that the Blue Knight had been injured in earlier in the day. The injury, however, came from Pudding having an accident while practicing a trick. Although Keiichiro is not shown to have any romantic interests in the manga, in the fourteen episode of the anime adaptation, he is shown to have an ex-girlfriend named Rei Nishina, a researcher studying butterflies.
