Member of the bike gang "Shounan Bakusozoku" and former Shiyou Middle School's boss.

His motorcycle is a Kawasaki KH400

In Japan, the country that inspired the slogan "Born to be Mild," the blood of young men still runs hot. In the old days they'd go off into the country and hack each other up with swords, but these days, what with school, that isn't very practical. 
So some of them do something very un-Japanese. They strap on a big bike, roar around annoying people, and pound anyone they consider dishonorable. 
Now meet Eguchi Yousuke, leader of a high-school Biker gang AND the school's handicrafts club. Which means he divides his time between fistfights and fancy needlework. 
And if you think he's weird, wait until you meet the rest of his gang... 
(Source: AniDB)

[Profile](https://www.aoni.co.jp/search/sato-masaharu.html)

The Shonan Bakusozoku are the toughest riders there are, and they're only in highschool! But that's nothing compared to their leader, Yosuke Eguchi. His love of motorcycles is second only to his love of handicrafts!

Kakuji Marukawa