Responses
I think that they are real brothers because In one of the panels of the last or second last chapters is a phone conversation with their mom saying that the dad is part african wildcat or something. I might be wrong though, so feel free to correct me.
Are they ACTUALLY half-blooded brothers or not? 'Cause they were introduced as brothers with the same dad and different moms. But, then they went on and on about "not being brothers". Yet, after that, Mi-chan mom denied excuse of cheating on Mi-chan's dad and said "that pest of an old man is part thingy-ma-jig wildcat" which I thought it means the dad is a lion with wildcat's recessive genes or something... So, they're really half-brothers, aren't they?
I feel like this stood the chance of being shounen-ai up until the phrase "not being brothers is fine" and when the truth that they're actually really brothers was revealed...it went back back to being a family comedy manga (●￣(ｴ)￣●)