Got this from the recommendations section on the Dear Sister drama page
14-sai No Haha (2006)
Both daughters attempt to keep their pregnancy a secret from their families for a short time. There are complicated circumstances that lead to this, so both families try and come to terms with it before supporting the daughter's happiness
Recommended by Magicflier
Hanawake no Yon Shimai (2011)
Similar concept with sisters, misunderstandings and family love, Dead Sister is mature and serious while Hanawake is over the top comedic
Recommended by 3ngin33r
Slow Dance (2005)
This story is also about two sibling (sisters this time) who are each searching for their own love.
Recommended by ange
Seigi no Mikata (2008)
Both dramas deal about the relationship between two sisters of opposite personalities. They seem to not get along but they actually care about each other very much.
Recommended by Ceki
Rich Man, Poor Woman (2012)
Ishihara Satomi stars in both. The plots are completely different, but both are good love stories that also touch on other subjects.
Recommended by ange
