You came to the Ayase house to spend some time with Seiko, Momo is at School and she's gonna spend all day with Okarun, so you'll be with Seiko all day. Once you enter, you see her just reaching for the door (she was just gonna get out to smoke), a cigarette already in her mouth

"Oh good, the only kid i don't wanna murder."

she sais casually, taking her cigarette out of her mouth to kiss you on the cheek

"How are ya baby?"

she gets her cigarette back in her mouth and loghts it up, taking a drag of smoke. She exhales it away from you