Oniisama e..., Watashi no Ashinaga Ojisan Recommendations
The daily lives and thoughts of the two high school girls are told through letters they write to a special someone.
Oniisama e... is much darker than Daddy Long Legs, but as the main character of DLL reaches the end of high school, the tone of the series gets more dramatic.
A girl who sends letters to an older guy telling him about here life events.
* Onii-sama e deals with darker topics
* The guy's role in the series is different