70s, Japanese, department store bike.

I think that the guy's shed was leaking...

There is a lot of work that needs to be done here (and a lot of $ that needs to be put into this to make it rideable) which you may or may not want to do (because it is a heavy bike, and there are better alternatives)

but here is the order of things:

- try to get the seat post and the stem out of there. If you cannot, junk the bike. It will not worth your time/money.

if they are out:

- strip to to bare frame (junk everything with rust on it; well that's pretty much everything else) and clean it well inside and out.
- get parts to build it up
- build it up

that's a huge uphill and it's up to you whether you want to take it...