|Japanese name:||大沢 賢治|
|Voice actor:||Atsushi Ono|
Kenji Oosawa (大沢 賢治, Oosawa Kenji?) is a biological researcher and also one of the protagonists of 428: In a Blockaded Shibuya, he is Maria's father and is known for developing a cure for the Ua virus infection. He makes a cameo during the terrorist attack on the Shanghai International Conference Hall, bringing in stockpiles of Ua anti-virus medicine after a staged assassination.