so, saya dah tengok till episod 7 (english subbed).my 2 cents: Manami (elder sister) support their mother's pregnancy. same goes to the younger brother (Kouji). the elder son (Taichi), seriously i don't know either he agree with the news or not as the story more focus on him being threatened by his real father (he's actually an adopted child) and the younger sister (Miko - if I'm not mistake) , totally don't agree with the pregnancy. and so the story goes around with Kouji's illness. the leukemia relapsed (as till episode 7th) ... he's hospitalized but without no one know bout that (even his family) but somehow his elder sister found him in hospital (his sister's editor being hospitalized at the same hospital due to some illness). so, here his sister knew bout that (the leukemia) and Kouji ask his sister to not ever tell their mom as he don't want their mother to be a donor (it will risk the baby if their mother decide to do the transplant). but at the end of the episode (7), his sister asking Kouji to tell the truth to their mom (and i think they will as there's a preview for the next episode).
move to Taichi, seriously, in this episode (7), i hate Taichi the most. he only care bout the threat rather than the family. seriously i hate him >.< same goes to Miko
