Enigmatic Japanese fetish artist known by the pseudonym Namio Harukawa has passed away last week, according to an announcement by video game producer, Yuko Kitagawa.

Harukawa began his career in the '60s working as an illustrator for pornographic magazines. In the early '70s, his work for Kitan Club magazine gained him notoriety among SM enthusiasts. However, it wasn't until the end of the '90s that his artwork began to achieve international recognition.

His striking depictions of enormous face-sitting femdoms dominating and humiliating their diminutive male slaves caught the attention of celebrities including Madonna, the avant-garde artist Shūji Terayama, and celebrated author Oniroku Dan.

Today, his two-volume collection, Kyonyū Katsuai, is considered to be a collector’s item, while his whimsical illustrations of sexualized smothering and erotic asphyxiation proliferate on Instagram and Tumblr.

Still, very little is known about the artist. In fact, Dazed points out that it's unclear if he was 72 or 73-years-old at the time of his death.