'We've long since outgrown the thousand square feet of space at our Buchanan Street store,' says Kenny Penman, one of the owners and directors of UK-wide sci-fi and fantasy retail chain Forbidden Planet. 'I remember building that place by hand – when we started we were a comic and science fiction bookshop, but now we also sell Manga merchandise, statues, toys, Pop figures, games; everything under the sun to do with entertainment and sci-fi fantasy retail. That stuff takes up twenty times as much space as comics.'

That's why this month, Forbidden Planet Glasgow will make what's undoubtedly a bold move, both in the current high street retail climate, and also in terms of a comic shop industry which has seen lean times recently; although Penman says that FP is now an entertainment store. Thirty-two years after the FP store on Buchanan Street opened, it will move premises to the former River Island on Sauchiehall Street. 'The building's about 9000 square feet, so in effect seven-and-a-half times the retail space we have now,' says Penman.

For the many loyal fans of Forbidden Planet Glasgow – which originally grew out of Penman's ownership of the former Science Fiction Bookshop in Edinburgh, and a link-up with the then-developing, London-based FP chain – the cramped but stacked-high confines of the soon-to-be-former FP store are much-loved, whether the customer's interest is comics, graphic novels or toys. All of these established regulars will undoubtedly come to the new store, but the aim is that greater numbers of casual shoppers will also be drawn in.

With the Marvel and Star Wars franchises – and the electric word of mouth which greeted Joker – dominating the cinema box office, there's a huge audience out there. 'When we started, being into comics was quite a geeky thing,' says Penman. 'Now everyone watches Game of Thrones or Stranger Things or Avengers movies. This will be our largest store outside of Dublin, and I believe the biggest store of its kind in Britain, so there's a lot of potential there.'

For old-school comic collectors, there's also a return of the back issue section, which currently stocks around 3,500 issues; although when the planned third floor opens, that will be extended to 20,000. 'There will also be more Pop toys, they're huge right now,' says Penman. 'We're reintroducing our science fiction and fantasy novel section, which we haven't had in a meaningful way for ten years; a tabletop gaming section, which we haven't had space for before; and more events, hopefully at least every week or fortnight, from comic launches to book tours, and women-only and LGBTQ events.'

To add to the unique nature of the store, famed Glasgow-based comic artist Frank Quitely has created an exclusive Superman mural, and there's an eight-foot Chewbacca figure for customer photo opportunities. 'The fact that retail generally is under pressure has given us this opportunity,' says Penman. 'We couldn't have afforded a Sauchiehall Street rent five or six years ago, but now we have this opportunity. It's a big deal for us, but I hope it's also a big deal for entertainment retailing and for Sauchiehall Street as well. These streets need independent retailers, I'd love to see more shops like us eventually come in.'

Glasgow's new Forbidden Planet store opens at 122–126 Sauchiehall Street, Glasgow, Sat 9 Nov.