From AQUA Scans:
Every little girl dreams about finding her prince charming and becoming a bride! Nursery school-age girl Rino is no exception. Precocious Rino falls in love with the timid and weak but very handsome and kind Kazuki, a career nutritionist at her school.
And so, carried forward by that love, she declares firmly to her love in front of other adults, "If you marry me, I'll definitely protect you!"