Moving out of a village: how to tell people?

For some background, I’m an ALT who has lived in a very inaka 集落 for more than four years and I’m moving for graduate school starting in April. I’m not exactly part of the village but I do talk to my neighbors, they help me out, and I have lived here a long time. Because of this, I’d feel bad about just disappearing one day with no goodbye.

For now I am sworn to absolute secrecy by the BOE (that’s some separate BS) but when I am allowed to tell people, is there some etiquette I should follow? My concern is because I am not allowed to tell anyone until late March I may not get the chance to tell everyone in person, however gossip travels fast out here so reasonably everyone is going to know. One idea I had was to make postcards explaining that I am moving for graduate school but again with how fast gossip travels everyone might know anyway so I don’t actually need to tell them.

Is there a right way to do this? I’ve heard of giving gifts when you move in (that is mostly obsolete) but don’t know much about moving out of communities like this, just moving into them. When my coworkers transfer they always give gifts, so is moving similar? I’m going to miss this inaka life, a big part of that being my lovely neighbors. These people have been so kind and welcoming to me, I’m just not sure how to repay their kindness when I leave.

by Dojyorafish