Naoki Matayoshi is a Japanese manzai comedian and author, who found fame performing as part of the popular comic duo 'Peace'. Spark is his first novel and has been hugely successful in Japan since it was first published in 2016. It has won the Akutagawa Prize and was adapted for film, stage and TV - the hit series is available on Netflix UK.

Shinsuke Yoshitake was born in Kanagawa Prefecture. He received first place in the sixth MOE Picture Book Award and Art Prize of the 61st Sankei Children's Book Award for Ringo Kamoshirenai (It Might Be an Apple), first place in the eighth MOE Picture Book Award for Riyu ga Arimasu (I Have a Reason), first place in the ninth MOE Picture Book Award and a Special Mention Bologna Ragazzi Award for Mou Nugenai (Still Stuck), and won the 51st Shinpu Award for Konoato Doushichaou (What Happens Next?).