He was the oldest, biggest and most aggressive of the litter.
Unlike his brothers, he is white.
The oldest puppy is born small like his brothers, but he is still biggest and strongest of them.
The oldest puppy pushes away his brothers and wants to be the only one who can suck milk from their mother. Kazuhiro even has to put him inside a box for a while so that the other puppies can have milk.
When the puppies are around 3-month-old, the smallest puppy grows tired of the attitude of his unfair bigger brother and attacks him. The spoiled big brother is easily beaten by the smaller.
Next day, Uncle Hiroshi comes to visit and decides to take the biggest of the puppies. He is pleased as the puppy doesn't even whine and others are pleased because the oldest puppy cannot bully the younger ones anymore.