Keiichi Wakaouji (若王子 圭一 Wakaōji Keiichi) is a fictional character in the series Full Moon O Sagshite. He is known to be Mitsuki's doctor, and a former band member of Route::L.

. At the start of the series he has given up music, but he later returns to the music business in order to find the missing Mitsuki, and becomes Fullmoon's producer.

In the manga, he falls in love with Ms. Oshige, and the two are married by the end of the series.