Kono made his professional debut at the Korakuen Hall in November 2000, losing on points to Toshiaki Niita.
[2] In September 2008, Kono fought Nobuo Nashiro for the vacant WBA (Regular) super flyweight world title.
[4] Kono's career suffered more setbacks, dropping decisions to Yota Sato and Yohei Tobe following his loss to Rojas.
[6] Yota Sato, who held the WBC title expressed interest in rematching Kono in a unification bout.
[7] Kono would lose his title in his first defense, dropping a majority decision (113-113, 112-114, 111-115) to Liborio Solís in a fight where both fighters traded knockdowns.
In a scrappy brawl that saw both fighters lose points on the scorecards due to fouls, Kono retained his title, dropping Kameda in round 2 en route to winning a unanimous decision (115-109, 113-111, 116-108).
[11] Kono would lose his title in a unification bout against the WBA's interim champion Luis Concepción.
[15] In his next bout, Kono faced Jason Moloney, ranked 4# by the WBA, #5 by the WBO, #11 by the IBF and #13 by the WBC at bantamweight.