usually when manga's or even books, r adapted into movies or drama's they usually fall short as u can't really get all the nuances and info that u have in "written" form, into the visual one - i found and read this manga cause i previously found and loved the 3ep J-drama adapted from this manga - and it was page for page the same (there maybe minor changes, but it doesn't effect the message of character's a bit) this was so good and sweet and as i totally loved Kana in the drama. i loved her character even more here - she is just extra and wish there were more pure hearted kids and adults like her out there - the world would be a better place.
Vol 4 Ch 8
Otouto no Otto