People react to covered tatoo?

Hi,
I heard recommendations of covering up your tatoos if going to an onsen, gym or beach or something like that. However, that would most likely make people understand I do have a tatoo (or an injury). Would people be offended by that and make me have to leave the facility?

If you can't see the tattoo, you can't have a reason to assume there's a tattoo.

The issue is not that you have a tattoo, the issue is that showing it affects the image and mood of the place.

Sorry for being a bit of a worryguy but wearing a bandaid wont make people think I have an injury (which might carry bacteria or something)?

Technically speaking, that can happen. Many public bath tubs and pools have signs forbiding users with injuries not yet healed.

Meanwhile, here is a list of places where people with tattoos have enjoyed in the past.
http://tattoo-spot.jp/