First appearance: Battle 9

Age: 45

Height: 174cm

Weight: 68kg

Type: Dou

Type: Katsujin Ken

Martial Arts: Marksmanship

Shirahama Mototsugu is Kenichi and Honoka's protective father and Saori's husband. Mototsugu is a middle-aged man with short dark blue hair and a fairly lean figure as he keeps himself in descent 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.

He 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 choose to try to bring him home by force after hearing of how cruel his training in his dojo. And when Honoka asks if Tanimoto Natsu could come over he prepares to use his shotgun Sebastian on him.

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 "anata."

He has two shotguns named Sebastian and Maximilian, which he often tries to take with him in order to take back Kenichi from the Ryozanpaku 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 Ludwig) 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.