Ollie Hartmoed grows up in a completely dysfunctional family, with divorced parents, a paternal grandpa of 99, maternal grandpa Luc was just left by grandpa for failing to spontaneously offer an appealing retirement project. Olie has to move in with ma's new partner Ralf Klein's family, which has three sons already, but hopes a surprise wedding party will spread happiness among the family. Because the country's largest draperies shop bears the family's name, Ollie chooses those as present. His neighbor girl Germaine, daughter of alderman Tulp, seems as perfect to him ...
Ollie promises Germaine to help her spread friendship worldwide by baking and distributing cake. That proves difficult in the overpopulated kitchen, but worse to pass out the pieces for various reasons. Meanwhile Greg takes the kids to the movies.
Ollie endangers his best friendship, jealous about Germaine, but noble Momo generously saves it during judo class. Grandpa Spatelplaat's job and pension are in danger because of adulteress grandma, who is duly cleaned out by her younger, smarter lover. Rolf is in rehab, Tobias is desperate to protect a secret. Alderman Tulp launches a municipal contest for the most remarkable family.
The Hartmoed draperies shop is in financial trouble and about to be auctioned. Ollie thinks his world is crumbling down, but grandpa sees a great opportunity. A clause in the sale of the family firm to the present owners gives relatives a preferential right to bid. Alderman Tulip weds the bad grandmother as dummy to bid against the united front grandpa organized to get the firm back cheap.