Secret X Siblings

shirosaki rinko is a high school girl who really loves children. she helps out at the kindergarten that her younger brother attends. also on the way home from the kindergarten are tsuga-kun, a fierce-looking delinquent, and mogami-kun, a bespectacled cool-guy who gives off an air of disgust. you might think they're all unrelated, but that isn't the casemaybe? a raising-esque (?) youth x parenting 4koma!!