I am going to guess that Kiroranke is going to betray them ,not just because the story is foreshadowing, because the way he is frame in the picture referencing the last supper. In the that picture he is in the place where Judas was siting in the original painting. Judas was the man that betray Jesus if you didn't know
Eh... Though I enjoy information I wish they didn't add those two particular info on the end.
Also I've been thinking this for a while but their group is similar to Momotaro. Asirpa is Momotaro. Sugimoto is the dog. Shiraishi the monkey. Kiroranke the bird.