Oujitachi wa Izonsuru Manga

http://mangafox.me/manga/oujitachi_wa_izonsuru/

When I first read this manga I thought wow this storyline is wicked, I love this mangka's artwork.

Ice blossom SUM:
18 year-old Yoshino is in love with his sister, Himeko, who has brother complex towards him. Yoshino and Himeko's father remarriage introduced new members to the family. Tsubaki, who is of the same age as Himeko, is as beautiful as a bisque doll. This new step-brother plans to expose Yoshino's secret feelings for Himeko. Yoshino thought that the underlying reason of Tsubaki doing this is because he likes Himeko too. However, never did he expect that Tsubaki was doing this for. . .