Mototsugu is a tall middle-aged man with short dark blue hair and a fairly lean figure as he keeps himself in decent shape for a man his age.
He's typically seen in suits from work or just ordinary shirts when around the house.
As a young teenager, he was less lean and had more hair on the top of his head that was more full and smooth.
Mototsugu is gradually impressed with Kenichi's growth as a man but feels sad that his son is growing further and further
away from him. He often acts in a goofy and rather foolish manner and is usually used as comedic relief of the series with his over-protective attitude when it comes to his sons' well-being, especially when he prepares to use his shotgun, Sebastian, to get his son back. He even chooses to try to bring him home by force after hearing of how cruel his training in his dojo. And when Honoka asks if Natsu could come over he tells her to do it while preparing to use his shotgun Sebastian on him.
He tends to be aggressive, which is natural for those who possess the Dou Ki, especially to strangers who come close to his family and those who he believes them to be hurting his family, which make him an overprotective family-man. Mototsugu himself stated that he would sell his soul o the devil for the sake of his family. He was shown to encourage his son on his decisions sometimes as shown when he gave a speech before going to the D of D and when he stood by his son side when he wanted to go and see his old friend Ryuto and told his wife and daughter to grow up and that for men when it comes for friendship they must go.
His wife, Saori tends to make sure he doesn't do anything too rash or embarrassing towards their children, especially Kenichi. He claims that he was quite popular with women Kenichi's age and Saori often left him love letters for him. However, in truth it was him who gave her tons of love letters to win her affection, which actually worked. She usually has to knock him on the head to keep him from doing something drastic in comedic relief. However despite this, the two love each other very much and she's often impressed by his actions of bravery and seriousness when it comes to their son, as she always calls him "Honey".
He has three shotguns named Sebastian, Maximilian and Rotowski, which he often tries to take with him in order to take back Kenichi from the Ryōzanpaku dojo, however, his wife manages to stop him every time. Despite his foolish attitude, he is actually very skilled in its use (good enough for Shigure to say that he was pretty good), and when he finally shows up at the dojo (with a new hunting rifle his wife doesn't know about, named Rotowski) he is able to carry Kenichi under his arm, the gun in the other, reload while on the run, and has a good enough aim to stop Shigure's traps. He later wins a prize in clay pigeon shooting. He is shown to have some strength enough to break a cup with one hand while being angry though his strength is not enough to open the door of Ryōzanpaku.
Despite his attitude, he is a legitimate master class fighter. Being able to evade the masters of Ryozanpaku while carrying Kenichi, being able to evade and counter the attacks of Shigure and being able to reload a lever-action shotgun by rotating it around the action with a single hand, something which Shigure herself said was impossible.
- Single-handed reload: Mototsugu can use one of his hands only when reloading his lever-action shotgun by spinning his shotgun.
- Backward shooting: Shoot the target or other things such as place where the target is standing in order to do a surprise attack or getting chances to escape. Mototsuku can use this shooting method without any watch or aim. While maintain do not causing direct harms to his target (Shigure).
- The name Mototsugu means "ex" (元) (moto) and "next" (次) (tsugu).
- Mototsugu's surname Shirahama means "white" (白) (shira) and "beach, seashore" (浜) (hama).