Sankakuboshi no Horobi no Yama

On a planet existing remote from other planets in space, there extends a land of white ashes. Organisms that resemble a triangular rice ball inhabited the land. The planet was once a place where humanity built a civilization. One day, something that looks like a human wakes up...

(Source: MANGA Plus)

Sankakuboshi no Horobi no Yama was published digitally as an English simulpub as The Mountain of Remains on Planet Triangle through MANGA Plus.