Miraroma: Miracle Romance Strawberry Scramble

The protagonist is happily living with his parents and his younger sister. One day a nun throngs into their house explaining that he is cursed because of the mirror he accidentally broke a day before. Apparently, the curse put the whole world into danger. The nun insist that he should be monitored 24/7 and will therefore start living in their house. So as to not to be a freeloader, the nun, who happens to be a super rich ojousama, put up a large sum of money which overjoyed and caused his parent...