|Wins by KO||6|
|Championships||JBC Lightweight Champion|
|Manga Debut||Round 912|
|Anime Debut||Does not appear|
Iga first appeared in chapter 912, in the first round of the Class-A Tournament to fight against former JBC Lightweight Champion and one of the tournament's contenders Imae Katsutaka. The Kamogawa group watch from the changing rooms, with Aoki who already passed to the second round of the tournament, wanting Imae to win in order to face him and settle their grudge match, since their match for the Lightweight belt while Imae was still the champion ended in a draw.
However, a huge upset was made as Iga completely demolished Imae, winning by KO in the very first round of the match. It is then that the Kamogawa group realise that the man in his corner is none other than freelance trainer Baron Kurita, a former Kamogawa gym member.
Iga appeared again in the Class A Tournament finals to face Aoki Masaru. Iga quickly showed his intentions by knocking down Aoki in the first seconds of the match. Aoki managed to get back to his feet only for Iga to nail him again. The first rounded ended with Iga's complete domination.
As the match continued Iga kept beating Aoki with ease, despite the latter's attempts to use his trademark moves. He continued pounding Aoki with no intention of finishing him off, only to make him suffer as instructed by Kurita. Tomiko, who was still watching, couldn't help but cry and scream in sight of her loved one beaten so badly; Iga called her an ugly pig, much to Aoki's frustration.
Kamogawa Genji stated that Iga manipulated Aoki with hand eye feints, making him enter dangerzones without him realising it, something that doesn't happen unless there is a huge gap in their skill.
In the 7th round, Iga asked Baron if that was enough, and Baron gave the okay for him to finish Aoki off. Iga then proceeded to end the fight, KOing Aokiand at the same time Shinoda threw in the towel. With this victory, Iga completely won the Class A Tournament, subsquently became the 1st seed in JBC and earning the right for a title shot.
After the match, in the corridors of Korakuen Hall, Iga saved Baron from Takamura by grabbing Takamura's arm as he was about to throw a punch. In response, Takamura grabbed his hair and asked him if he was "gonna bark for Kurita" since he trained him. Before leaving, Takamura warned him and Baron that their actions weren't going to stand and that the day would come where they would whine like dogs.
|WIN||10-0-0||Oushima Souji||TKO||6(10)||N/A||Tokyo, Japan||Wins JBC Lightweight Title|
|WIN||9-0-0||Aoki Masaru||KO||7(8)||1997||Tokyo, Japan||Class A Tournament Finals|
|WIN||8-0-0||Imae Katsutaka||KO||1(6)||1997||Tokyo, Japan||Class A Tournament Round 1|
|WIN||1-0-0||Unknown||Decision||4(4), 3:00||N/A||Tokyo, Japan||Pro Debut|
|Preceded by||Title||Succeeded by|
|Oushima Souji||JBC Lightweight Champion|
? - present
Iga is a lean, well-built man of average weight, black eyes, and black hair that partially covers his forehead. He has a prominent rectangular nose and narrow eyes that give him a perpetual look of boredom regardless of the situation.
Iga is shown to be stoic and near void of emotion, rarely speaking or even displaying a change in demeanor. He is characterized by his bored and lazy expression as well as an eerie amount of calmness (or airheadedness) solidified by the fact that he rarely bothers replying to his trainer during his class-A tournament match against Aoki.
It is implied both indirectly and through Takamura Mamoru that Iga is unbelievably loyal to Kurita. As seen in chapter 976, Iga protected Kurita by stopping a prepared punch from Takamura that would've landed should Iga not be there to restrain it. This loyalty is most likely conditioned from Kurita's brutal training regimes, which, as stated by Kurita, changed Iga from his 'soft' self to the immensely strong KO puncher he is today.
It's known that at the beginning of his career Iga only won by decision, but after Baron Kurita became his trainer he won by string of KO's, a fact noted by Kurita himself. Testaments of his boxing skills come during his fight against Imae Katsutaka, a former champion whom he KO'ed in matter of minutes, and in his match against Aoki, a seasonable veteran with skills equal to that of a national champion: he completely manipulated Aoki with eye and hand feints, something that never happens unless there is a huge gap in skill between boxers.
- Iga is largely based on first black heavyweight champion Jack Johnson for his ability to simultaneously beat and control opponents.
- Iga Shinobu's name might probably reference the historical Ninjitsu school (the Iga-ryu) and Shinobi (another word for Ninja) as the Kanji for his full name is the same as the Kanji of the aformentioned two references