This picture Sukai found when him an Tenkuu left on a mission a couple of years back to find his clan memeber.
The guy in the black with blue hair is his dad: Yoite Altai
The woman in the red is his mother: Miyu Altai
His brother is the little red head that his mother is holding: Soubi Alati
And he's the blue headed one that his dad is holding.