Japanese animator Osamu Kobayashi, best known for his work as a director, writer and animator on international sensation Naruto Shippuden, died April 17 after a two-year battle with kidney cancer. He was 57 years old.

News of his passing was shared via his Twitter account in a first-person message that noted (in Japanese), “It is regrettable, because there are still things I wanted to do and projects I wanted to make. When I am reborn again, I will surely create some great works! Adios. The eternal 23-year old.”

Kobayashi was born January 10, 1964, and began his artistic career straight after high school primarily as a designer and manga artist. He worked as a world designer on the RPG Grandia, then took a similar role on the anime OVA Blue Submarine No. 6. Operating between the videogames and animation spheres for a few years, Kobayashi soon transitioned fully into the world of anime and took on more creative responsibilities. He directed his first short, table&fishman, for Studio 4°C’s avant-garde shorts collection Digital Juice (2002). He went on to notably direct the Beck: Mongolian Chop Squad TV series and Paradise Kiss, as well as contributing to popular series Gurren Lagann, Panty & Stocking with Garteberlt, Lupin the 3rd Part IV and Dororo.

An online memorial site in English has been set up for Kobayashi’s overseas fans to remember the artist.