Tomorrow is "Kodomo no Hi", which means "Childrens Day" but is more of a holiday for boys. Each household displays carp shaped flags or streamers to declare that they have healthy sons.
I imagine it was originally advertising for other peoples healthy daughters.
The first flag is called the "Fukinagashi" and represents a river. It bears the family crest, or in our case two family crests. Mika's is a stylized plum blossom.
The Craig crest is a knight with a broken lance with the declaration "J'ai bonne esperance", I am of good hope. It's a long story.