With On A Sunbeam (named after a Belle & Sebastian song), Walden has created an expansively imaginative universe with the “wow” level of a Hayao Miyazaki film, using it to frame a thoughtful and nuanced tale of romance, companionship and coming of age. It’s the sort of graphic novel which feels a little difficult to write about without spoiling any of the gradually unfolding wonder for any would-be reader. We discover this universe page by page, along with the protagonists, and it’s never less than a joy. At over five hundred pages, it’s a densely-packed book that allows for an indulgently slow read, but also has the page-turning pace of a good mystery – the sort of book where you’ll want to keep reading it straight through, but will also be reluctant to finish too soon.

As well as showing obvious influences from Studio Ghibli in the animistic wonders populating its outer cosmic fringes, I’m also reminded a little of Love & Rockets, in the down-to-Earth-in-space believability of our protagonist, budding space mechanic Mia. In more traditionally literary terms, the first half also recalls Violette Leduc’s bittersweet tales of boarding school romance; the heart of this book is the unfolding relationship between Mia and shy bookworm Grace, who meet at (space) school as 14-year-olds, a narrative told in parallel as we also meet Mia’s fellow crewmembers on their fish-shaped spaceship in the present, some six years later.

Formally, it’s a subtly adventurous comic – these separate timelines often dissolve into one across a page or even within a single panel, and other similarly bold panel arrangements show a confident and fluid approach to the medium. There is much wonder to pore over, with tighty-composed images of fantastical architecture and brooding landscapes doing a lot of the work in keeping Walden’s subtly sketched out universe together. The restrained palette of the colouring is exceptionally beautiful, even more so in its printed form (the comic was initially serialised online, and is still available to read there for free). Walden uses imagery and motifs which will be familiar to readers of her previous work; her dream-like visions of buildings floating free of foundations and fish swimming around rooms here find themselves solidified into a truly original vision of an uncanny but magical future, whilst also acting as poetic abstractions of memory and mental process. I’m reminded favourably of Taiyo Matsumoto, whose ouevre also incorporates repeated personal tropes, despite spanning many genres and story types, adding a biographical weight to his body of work – Walden has only just begun building her world, but it’s clear that hers will be a voice that stays true to itself, whatever it may be saying.

In an inspired move, the book is set in a universe with only one sex, while still retaining the full natural spectrum of gender (including, notably, a non-binary character). This in some ways creates a tabula rasa, free from being shadowed by the sexual politics of our world. It also means that if you like strong female characters, you’re in luck – this book has about twelve of them, with compassion as a sign of strength a repeated note. What’s even more remarkable about the non-binary character, Ell, is that they are mute, yet we quickly feel that we know them. An exemplary case of “show, don’t tell”, it highlights how well-drawn all of the individual personalities in the book are.

For all of its jaw-dropping landscapes, sci-fi wows, intricate plotting, clever gags and pin-drop romance, this is ultimately a book about relationships, and specifically about families – both those we’re born into and the ones we choose and forge for ourselves. These complex and believable living characters and relationships anchor the story, allowing the more abstract and magical elements of its universe to feel normalised. We somehow feel included in the rag-tag ad hoc family at the centre of this book, and it’s a joy to follow their adventure with them.

On A Sunbeam by Tillie Walden is available now via Avery Hill Publishing.