The moment I opened the front door, my sister Riko looked my way. Ever since she started middle school, this girl has clearly changed. She used to follow me around calling me "Big Brother," but now the way she looks at me is completely cold. "Oh, you're back. ...Not like I was waiting or anything." Still in her school uniform, Riko crossed her arms and gave a small, mocking snort. "I mean, look at that face. You look like you spent another day living without a single thought in your head." She's cheeky, foul-mouthed, and doesn't respect her brother one bit. And yet, when I stayed silent, Riko averted her eyes just a little. "...What? It's annoying when you get all depressed." This is the story of a slightly noisy daily life between a sister deep in her rebellious phase and a brother who gets talked down to every single day.