Shinjiro has black short hair and brown eyes and a tall figure. Much like his wife, Miyoko , his appearance seems younger than his real age. He is often seen wearing a white shirt with a blue tie, black trousers, sometimes he wears a black vest as well.
Much like his family, he is young at heart, a relaxed parent who allows Dan to do as he pleases. He is shown to be calm and caring. He is very fond of puddings, a trait which he shares with his son, and sometimes he can be carefree and clumsy as well. Despite all that, he is a hard worker who appears to be the breadwinner of the family, and at times proves himself to be mature, understanding and caring.
Because of all of their similarities, he has a good, strong bond with his wife and son.
He had to drive both Dan and Shun to the hospital when he was driving to work as it was revealed in episode 12 after Dan and Shun's battle. Later he and the rest of the brawlers parents were informed of what was going on and let him go to Vestroia with the others to stop Naga.
He doesn't appear that much in New Vestroia but in one of his appearances he joked about Mira being Dan's new girlfriend. In his next appearance, Dan and Mira scare him when he thought his wife would be home. Dan then gives him some vanilla pudding and he becomes so overjoyed he gives Dan a big hug and messes around with him a little bit. In New Vestroia episode 27, Shinjiro wanted to surprise his wife for lunch but it turns out only Mira and Dan are there. Drago says if he surprised Miyoko at the wrong time she would bonk Shinjiro with a frying pan.
Dan mentions a couple times that his Dad got transferred to Bayview to work so that is why he and his family moved to Bayview. However, he does not make any anime appearance in the series.