Fui ni Arawareta, Toshi no Hanareta Gimai no Hanashi
不意に現れた、歳の離れた義妹の話
A troubled teenager named Ryu is unexpectedly visited by his long-absent father, who introduces a girl named Suiren as his stepsister. She is twelve years younger than him. Their lives begin to intertwine as they navigate the new relationship. Initially confused by the sudden change, they gradually adjust, working toward building a bond as a family.
