wtf wtf wtf

it's all one incest domino?!

so basically, seizou (touma heir) and his sister hanae engage in incest and give birth to ranzou (eldest son). ranzou, while growing up, is ridiculed because people believed he's illegitimate since hanae never exposed who the father was. seizou marries mitsue, hanae's best friend. mitsue 'adopts' ranzou and gives birth to ikuro (second son) soon after. then hanae dies but not before revealing to mitsue that she seduced her own brother, mitsue's husband, so ranzou is actually their sibling-lovechild. mitsue then starts seeing ranzou in a different light and chokes him, depriving his young brain of oxygen, and ultimately leading him mentally handicapped(?). plus, i'm assuming the incest had already made him cognitively dependent so the choking was just the cherry.

after hanae's death, seizou because a psycho freak and starts grxping ranzou while thinking of hanae. he also starts isolating ranzou, allowing him human interaction only when he visits him. on the other hand, mitsue who goes crazy depressed is sexually and manipulated by norihiko, a young servant who also does the same to her son ikuro as the years go by, and especially following her death. after seizou's death, ranzou is able to go out more often (still accompanied) but at his late-20s he's too far gone.

at the end ranzou's been unfairly treated by everyone since he was a toddler. and even ikuro has no clue of how much his older brother has had to deal with. possibly, only norihiko may know (to an extent) of everything that happened???