Some people get confused, but they are owned by different companies. The founders know each other, has some relationship in business, and the company behind Hard Off owns shares of the company behind Book Off.

Yep, it's a chain with a bunch of different brands.

Biggest ones are Book Off (books, comics...), Hard Off (electronics, computers, musical instruments...) and Hobby Off (toys, collectibles, video games...).

They even have a Liquor Off ! (not second hand, just discount/overstock)

Yeah, same company. "Off" likely meaning discounted.

They are part of the same brand.