When I told my favorite child, my twin sister came with me as a bonus (1) / Kyoyu Brave Library
※Please note that product information is not in full comprehensive meaning because of the machine translation.
Japanese title: ライトノベル文庫サイズ 好きな子に告ったら、双子の妹がオマケでついてきた(1) / 鏡遊 ブレイブ文庫