七つ星
ななつぼし
family crest representing the seven luminaries (with one central circle surrounded by six other circles)
七星 is read as しちせい (shichisei) and means the Big Dipper (asterism).
しちせい
shichisei
あれは北斗七星だよ。
That's the Big Dipper.
星座は全然詳しくないな。オリオン座とカシオペア座くらいしか見てもわからない。あと北斗七星もわかる。
I know nothing about constellations. I can only recognize Orion and Cassiopeia. Oh, and the Big Dipper, too.