The joke is that Naoya says yes to both of them, and the show commits to that bit so hard it becomes genuinely hilarious instead of creepy. Traditional harem anime wastes time on guilt and indecision; this one just removes the indecision entirely and builds comedy from the actual chaos of dating two people who somehow don't hate each other. It's dumb on purpose, it knows exactly what it is, and if you're willing to laugh at a premise instead of think through it, the comedy timing carries you all the way through.

Naoya Mukai, a first-year in high school, finally has everything he wants: Saki, the childhood friend he has loved since grade school, has said yes to dating him, and he pours all his affection into her. Then another girl, Nagisa Minase, confesses to him. He turns her down politely, but her charm and persistence keep drawing him in. Unwilling to pick one over the other, Naoya proposes something outrageous: he will date them both at once, with both girls fully aware. What follows is a romantic comedy with ecchi and slice-of-life touches, built on the silly situations the three get into while trying to keep this unusual arrangement going.