Birthday: August 14, 1975

Homeland: Japan Tokyo,

Occupation: Professional Boxer, Makunouchi Fishing Boat worker

Weight Class: Featherweight

Height: 168 cm (5'6")

Reach: 168 cm (66")

Style: Out Boxer

Stance: Orthodox Stance

Current Affiliation: Kamogawa Boxing Gym

Trainer: Shinoda

The most recent addition to the roster, the charming Manabu has a prodigy's talent and was the captain of his high school's boxing team. Cheerful and a lover of bad puns, Manabu is a fierce outboxer with extremely high speed and reflexes and whose fighting style is uncanny in its resemblance to Miyata's. His most powerful technique is a furious hail of mid-power blows known as the Hedgehog or Porcupine, which was employed in an East Japan Rookie Kings showdown with his longtime nemesis, Kyosuke Imai. Outside of boxing, Manabu is employed as an assistant at the Makounouchi family's fishing business. Itagaki's character is based on former world champion Oscar de La Hoya for his prodigy-like natural ability and good looks, whom Itagaki has admitted to idolizing in the manga. 

He is a Featherweight out boxer renowned for his speed and genius boxing talent. His trainer is Shinoda Tomoyuki. He, along with Makunouchi Ippo, Takamura Mamoru, Aoki Masaru, and Kimura Tatsuya, round out the core members of the Kamogawa Boxing Gym.

Itagaki originally tried out and prevailed at many sports, but when he tried boxing he came across Imai Kyousuke and was defeated by him 3 times. In order to defeat him no matter what, he skipped college and instead joined the Kamogawa Boxing Gym, where his idol, Ippo, trained.

After Umezawa Masahiko retired from the Makunouchi Fishing Boat in order to pursue his own dreams, Itagaki took over his job and started receving the same kind of work training that Ippo goes through. He achieved revenge on Makino Fumito, who had defeated him in his debut match with a foul, in the opening round of the East Japan Rookie Kings. At the finals, after a tough fight with Imai, Itagaki captured the East Japan Rookie King title and seemingly tapped into his true fighting potential; his speed, reflexes and timing are now said to be at genius levels.