Koji Senoo is the father of Aiko Senoo, one of the main witch apprentices in the series Ojamajo Doremi DOKKAAN!. He is a taxi driver by profession and is first introduced living with his daughter in the city of Misora after separating from his wife, Atsuko Senoo. The divorce occurred when Aiko was very young, largely due to disagreements about Atsuko's demanding job and the emotional strain of a past miscarriage, leaving Koji to raise Aiko largely on his own. Physically, Koji resembles Aiko closely, sharing her blue hair and eyes, and he typically dresses in a suit and tie for work. His most defining trait is his deep love for his daughter; he works hard as a taxi driver to support them and often prioritizes Aiko's happiness over his own. This is demonstrated when his boss arranges a potential remarriage for financial gain, which Koji ultimately refuses because Aiko strongly opposes the union, showing he values his daughter's feelings above personal convenience. Koji has a straightforward and earnest personality, and his relationship with Aiko is close and affectionate, with the two often working as a team around the house and in their daily lives. Throughout the series, Koji's primary motivation is to be a good provider for Aiko and, gradually, to rebuild the family he lost. In Ojamajo Doremi DOKKAAN!, his role centers on his evolving relationship with Atsuko. Over the course of the season, the former couple begins to reconnect, and by the end of the series they reconcile and decide to live together again as a family, moving back to Osaka. This reconciliation marks a significant personal development for Koji, as he overcomes the pain of the divorce and regains the family unit he always wanted. In terms of notable abilities, Koji does not possess any magical powers; his strengths lie in his dedication as a father and his dependable nature. He is also known for his skill as a taxi driver and for his ability to work alongside Aiko in their home life. His key relationships are with Aiko, his daughter, and with Atsuko, his estranged wife, as well as with his colleagues and Aiko's friends. Through his steady support and eventual reunion with Atsuko, Koji Senoo illustrates themes of responsibility, forgiveness, and the enduring bonds of family within the series.