The 'Quemarla' tribe, where most of the tribe members are naturally skinny.
Their condition for becoming a 'Dout-Tuum' recognized by the tribe is the joy and satisfaction of the guardian god 'Jakai'!... However, due to genetic limitations, only unappealing sacrifices have been offered, so he is very angry.

Then one day, Koa, an abandoned child, appears to the Quemarla tribe while they are hunting. The chief, who noticed the child's sturdy and sturdy physique, decided to take him in and raise him as a proper 'Dout-Tuum' man, and
Koa, who successfully built a body through steady bulking, finally went to the three-day ritual as a sacrifice to the gods. I'm leaving...

“With your lustful body, it would be more than enough to save your tribe.”