Jitsu wa Imouto Deshita.: Saikin Giri no Otouto no Kyourikan ga Yatara Chikai Wake
じつは義妹でした。 ～最近できた義理の弟の距離感がやたら近いわけ～
A girl is introduced to her stepbrother, Akira, who was raised in a difficult family and is shy despite his good looks. The narrator, who had never had a sibling before, bonded with Akira quickly and developed feelings for him, believing they were brothers. After learning that Akira is actually her sister, the narrator is confused and conflicted about their relationship. Akira, meanwhile, begins to pursue a romantic connection, shifting from sibling to potential lover.
