Shunji Sonoyama (1935-1993) was a Japanese cartoonist best known for First Human Gyatoruzu (Hajime Ningen Gyatoruzu), a comic published Manga Sunday and other magazines from 1965 to 1975. It was turned into anime twice (one from the '70s by Tokyo Movie Shinsha and another from the '90s by Studio Pierrot). The 1970s anime is still being rerun in Japan to this day and was released on DVD.
Sonoyama also did other strips, including Ganbare Gonbe (1958-1992), Hana no Kakaricho (1969-1982), and Gatapishi (1979-1992). But one of the most unusual is probably this one, and I happened to have a copy of it.
It's called Kokkyo no Futari (Two Guys on the Border). It's a 32-page booklet that Sonoyama published himself in 1962. It's a series of one-panel cartoons featuring two guards on the opposing sides and their friendship. I took the liberty of scanning some of the pages below, along with the letter Sonoyama himself wrote (in English), signed and attached to the booklet.