Tell you what. Check on the elderly sole survivors who don’t have anyone checking up on them. Bring some community to them. Help them with their emergencies, things they have difficulty executing.
It is a different job, but should it be? Why can't they be cross-trained?
In Vancouver, the police are on the front lines of helping the homeless / drug addicted / mentally ill population (there's a very large overlap between the three groups) access shelters and treatment.
I can't speak to Japanese police, but in America you wouldn't want our police doing any kind of social work. The police here are just bullies who have been given badges and guns, and are exactly the wrong personality for any job that requires compassion. Moreover, they're extremely trigger-happy and are well-known to shoot people who are having mental health episodes.
Police are kinds of social workers, crime and threats to life are intimately social matters. I think in most countries police would respond to suicide warnings. Police spend most of their time dealing with mentally ill and stressed people who they more often just talk to than arrest. Carrying out welfare checks on elderly people is exactly what they should be doing in Japan, besides preparing for the next earthquake.
Maybe for substantive interactions, but merely going on patrol and ringing doorbell/greeting elderly who have opted in to the service wouldn't require very much. If they are literally without things to do, this would be one of the least destructive things they could do.
Incentives matter. You must enforce this from the top down, that law enforcement will be measured by community engagement. Action and results will follow.
