Onii-chan Dakedo Ai Sae Areba Kankeinai yo ne

Onii-chan Dakedo Ai Sae Areba Kankeinai yo ne summary:

After being separated from each other for 6 years since the death of their parents, fraternal twins Akito Himonokouji (brother) and Akiko Himonokouji (sister) had finally reunited together again during the holidays thanks to some planning from Akito, despite objections from both of their adoption families.
Being happy that Akito had fulfilled his promise to be with her again, Akiko confessed readily that she had incestuous love in Akito, and will not hesitate to do anything to win the love of Akito. Akito however does not harbor the same feeling for Akiko, and as a result had a headache with Akiko’s actions.
Despite all these, he still loves Akiko as a sister, and finds her adorable and cute, especially when he had not seen her since she was 10 years old.