Goro Natsume  

The doctor responsible for Rika's care was previously her physician at another hospital but has since been transferred to the facility in Yūichis town. As a result, Rika also moved there so that she could continue receiving his medical attention. Despite their professional relationship, this doctor harbors some feelings for Rika and tries to sabotage her relationship with Yūichi by claiming it's all just fun. In reality, Natsume is doing this out of personal experience as he lost his wife to a condition similar to Rikas and may not want Yūichi to go through the same thing.