Osananajimi to Kekkon Shitara Otsuki no Maid mo Yattekita Ken

Keiichi and Rion are fresh newlyweds. Once graduated from the school they married and reaffirmed their mutual love. Thanks to assets of Rion's rich family they move into a new house and prepare for their new married life. However Rion's parents, who fear for the future of young and inexperienced married couple, instead dowry give them young maid Yumiko to support them. How common life of those three will eventually turn out?