Kinnikuman is a very childish character. He complains when he does not get his way, pouts when someone gets more attention then him, and is often downright lazy. Early in the series, he would often refuse to fight certain monsters unless he got something in return. However, underneath this childish behaviour lies a very noble heart, and when times are at their worst, Suguru's courage surpasses that of the greatest of Seigi Choujins. He has been known to fight better upon realizing how shameful or dishonorable his opponent is being. His honor and friendship has warmed the hearts of several an Evil Choujin.
In the beginning of the series, Suguru fights Kaijū by eating garlic and growing 30 meters tall. Despite his great strength and skill, Suguru is quite clumsy by nature. This side of him causes most people to fear him more than the monsters he fights. He is so clumsy that, at times, regular people are capable of besting him in fights. He has even said on one occasion that although Choujin's wounds heal much faster than human wounds, when he gets hurt it takes longer to heal than a human, probably as a result of how he takes his training and fitness much less seriously than most choujin. He is also very arrogant and believes himself to be more popular than he actually is. He gets daily reminders of the truth, however, when people run from his ugly face or his garlic breath.
Suguru's favorite food is gyūdon, and he will do almost anything if he is offered just one bowl. Though he mostly eats gyūdon, he also pigs out on a wide variety of other foods, and when he is not eating he is usually watching TV. He "trained" for the 21st Chōjin Olympics by eating chips and watching TV. He is stationed in Japan in Beverly Park and lives there with Meat.
Suguru is also a bit lecherous and has been known to take part in matches he previously refused to simply because a pretty girl asked him to change his mind. Suguru flirts with every girl he sees, and has on numerous times tried to peep on his friends Mari Nikaidō and Natsuko Shōno. Unfortunately for him, no girls find him in the least bit appealing except for Bibinba.
However (and ironically), when Bibimba first shows up it is a one-sided love on her part and he finds her more annoying than cute. But by the time of the Seven Devil Chōjin Arc he seems to acknowledge her as his betrothed. During the Survivor Match for the Kinniku Throne Arc, he showed great concern for her when she threw herself from the stands and later admits that he believes they are bound by the red string of fate. Oddly, Bibinba is for the most part left out of the anime, and Mari, whom had always shown more interest in Meat, becomes his main love interest.
His personality is reflected in his voice in the anime, which deviates between high and screechy and low and serious.
In Kinnikuman Nisei, Suguru has lost his muscles and become skinny and flabby, but is still quite powerful. He has taken on a lot of the same characteristics his father had and is usually bickering with his son. Unlike with his father though, Suguru has a great deal of respect for Mantarō, and although Mantarō finds him lame they maintain a rather healthy father/son relationship. [Source: wikia]
You can download this papercraft toy here: Kinnikuman - Kinniku Suguru Free Paper Toy Download