Both comedies feature religious figures (Buddha/Jesus in Saint☆Onii-san and Satan/Alciel/[another that I won't spoil] in Hataraku Maou-sama!) rooming in Tokyo apartment complexes. The deities are shown living as regular people--worrying about expenses, fearing their landlords, etc.
Both are great comedies which display legendary saints and gods living in ordinary situations. Although in Sekkou Boys they are not the actual physical embodiment of these figures (since they are plaster), they still retain the same personality traits as them.