Well...i really LOVE this manga....it´s 100% recomendable for the ones who loves smutty and very cute stories..Although the main theme could be a little "weird" for some people ( incest ) Kotomi Aoki has made a very good job with this one.The art is great...Yori is SUPER COOL ( i cant say he´s cute ..because he´s more the cool type..but i like him anyway ^^
-The story is simple: Yori and Iku are twin brothers, and one day, Yori confess his sister that he has been in love for her since they were childrens. ( waaaa..they´re 15 years old...the´re grown ups now xDDD ) What will his syster answer to that confession?? well..i wont tell you the story...what i can tell you is that this manga has very sweet moments...the chibi yori is sooo cute...and the cool yori is sooo pervert xDDDD

The manga has already ended in Japan ( 10 volumes ) and its NOT licensed in English
i found a licenced version in Spanish...and it´s been published in Spain for a few months now ( they are now in volume 2 ) by editorial Ivrea

- There´s another story that is related to this : Boku no Hatsukoi ni Kimi ni Sasagu (secret unrequited love ) but here..the plot is REALLY SAD...i´ve really thought not reading it anymore...because i dont want to see the inevitable end..( i will take abput this one another time :) )
-you can download the english version of ""Bokuwaimouto.." from Shoujomagic
they´ve translated the manga till first chapter from volume 4. From there, Manga Abyss and Divine Sanctuary have taken the project...but they´re releasing it really SLOW , so we have to be patient ^^

here the links!

-volume 1,2,3 and ch 19/ vol 4 : http://savefile.com/projects/474189

-chapter 20,21,22, and 23: go graw them in the Manga Abyss forum ^^ you have only to register to be able to download the chapters..( no need for an amount of post to acess to releases )

and thre is an OVA from Bokuna!!!
i leave u here the first part...^^ ( with subs )