An adjustable height workout station for pullups, with built in arm bars for "Captain's chair exercises" for abbs (leg raises etc) and dips with a removable back support. It even has elevated paraletes for push-ups. This single piece of equipment pretty much has it all with enough variation to keep it interesting for years. It's really solid and stable, and doesn't make noise, it's fairly compact considering everything it does. It literally replaced my gym membership. It's still pretty much in mint condition even though I use it quite often. I've also added grips to the pull-up bar for ease of use. I still have the original box so it'll be relatively easy to transport.
The photos are from Amazon where it sells for ¥12,990. I'm asking for ¥7,000 which is a good deal but if you want to make me a fair offer, I'll be happy to consider it.