He won the fight by a first-round technical knockout, dropping Kosuke with several well place knees and hooks.
[3] Riamu was scheduled to make his K-1 debut against Lyra in the preliminary portion of the K-1 WORLD GP 2019 JAPAN ～K'FESTA.2～ on March 10, 2019.
He moved up to super bantamweight (55 kg) for this bout, a two kilogram increase from his previous fights.
[6] Riamu was scheduled to make his second K-1 appearance against Ryuto on March 22, 2020, on the preliminary portion of the K'Festa 3 card.
[8] Riamu was scheduled to face the former Krush Bantamweight titleholder Junki Sasaki at K-1 World GP 2020 Winter's Crucial Bout on December 13, 2020.
Additionally, Yoshioka entered the fight with a one-point deduction and was forced to wear the heavier 10 oz gloves.
[14] Riamu was scheduled to face Yuto Kuroda in the tournament semifinals, held at Krush 130 on October 31, 2021.
[20] Riamu faced the two-time Rajadamnern Stadium title challenger Mutsuki Ebata at The Match 2022 on June 19, 2022.
[28] Cecchetti withdrew from the bout on June 12, due to a toren left thigh adductor muscle, and was replaced by Angelos Martinos.
[29] Riamu won the fight by technical knockout, as he stopped Martinos with low kicks 20 seconds into the extension round.