Umon and Sanae are the trusted allies of Dr. Richard Vincent. They are very loyal to the Hospital, Dr. Vincent and to each other. I personally love these two for that reason. Their role is small, but their dedication, especially in their final moments proves that while they may be supporting characters, they have a firm grasp on their beliefs and their feelings for each other. They may survive the destruction of the Hospital, but they are aware that Dr. Vincent's body is being ravaged by the Beta Applicon and he will not survive much longer. They also realize that their own time is growing short and spend the remainder of their time together, clutching their hands together. Their loss is saddening, but they remained loyal to their cause and the ones they love until their lives ended.