Manga creator Mine Yoshizaki, best known for Sgt. Frog, recently went to the shore, where he left a sand drawing for all to see. This is it.
Yoshizaki first got his start making manga based on video games, before establishing himself as a manga artist. Besides Sgt. Frog, he's also known for creating characters and art for Otomedius, the cute'em up shooter based on Gradius.