Kuma was an anime figure collector before becoming a photographer, he met Keeki on a convention and took photos of her anime cosplay but he developed an interest in lewd anime figures and lewd modeling around that time. lolcows say he was Keeki's boyfriend but I can't find any evidence of that. Keeki took many softcore shotings with Kuma and a couple of cosplay shotings and then disappeared, they only collaborated for about half a year or so. I don't know if they fell apart in good terms.
Keeki posted part of the lingerie she used in her kuma photoshots on twitter, she also liked all the photoshots she appeared in with her social media accounts. She didn't show her face but still gave a nod on what photos are hers.