Ryota Kohama grew up with a passion for performance and creativity. During his elementary school years, Ryota and his childhood friend Toru Yamashita—future guitarist of ONE OK ROCK—formed the hip-hop dance group HEADS, along with members Takuya Uehara and Kohei Nakamura.

HEADS signed under Amuse, Inc., debuting in July 2000 with the single "Screeeem!" and following up with "Gooood or Bad!" later that year. The group became a familiar presence in Osaka's Kyōbashi and Tokyo's Akihabara districts, performing regularly in bustling shopping and entertainment areas. HEADS achieved moderate success, releasing multiple singles and an album before disbanding in 2002.

In 2003, Ryota and Toru briefly joined a larger dance unit called Ground 0, expanding their skills before gradually moving away from the dance scene. In 2005, Ryota made a minor acting appearance in the drama "Shibuya Fifteen (Sh15uya)", in which Toru played a lead role.

In 2005, Toru approached Ryota with an idea to start a rock band. Initially uninterested in music and hesitant about playing an instrument, Ryota changed his mind after discovering Red Hot Chili Peppers and being inspired by bassist Flea. This turning point led him to embrace the bass guitar and become a founding member of ONE OK ROCK.

The early days were challenging—Ryota admitted he felt intimidated and avoided speaking to vocalist Takahiro Moriuchi (Taka) for almost a year. However, his perseverance and chemistry with drummer Tomoya Kanki helped shape ONE OK ROCK's rhythm section.

As ONE OK ROCK's bassist, Ryota provides the rhythmic foundation that defines much of the band's sound. His basslines blend punchy grooves with melodic undertones, supporting the band's dynamic shifts between explosive rock anthems and emotional ballads. While he generally favors a clean tone, he occasionally introduces distortion for tracks like Deeper Deeper and Rock, Scissors, Paper, adding intensity to the band's heavier moments. His stage presence is energetic, often matching the band's high-octane live performances.

Although his main role focuses on performance, Ryota has also made rare contributions to the band's songwriting. These moments stand out as special because they reveal a different creative side of him that fans rarely see. He has co-written the powerful Mighty Long Fall from the album 35xxxv, the introspective Stuck In the Middle, and more recently, C.U.R.I.O.S.I.T.Y. from DETOX, a bold collaboration featuring Paledusk and CHICO CARLITO that blends rock with modern experimental sounds. In addition to lyric writing, Ryota has composed music for nearly twenty tracks, among them Eye of the Storm, Deeper Deeper, and early works like Lujo. His creative input, though occasional, adds a unique texture to the band's discography, making these songs particularly memorable for fans.

Ryota cites Red Hot Chili Peppers as his greatest influence, and traces of Flea's funk-driven approach can be heard in his bass lines.

Ryota primarily plays Warwick bass guitars, owning multiple Streamer LX4 and Streamer LX5 models in various finishes. He pairs these with custom-painted amplifiers, often collaborating with street artists for unique designs. Over the years, his setup has evolved to deliver both clarity and depth while complementing the band's shift toward international rock sounds.

On February 18, 2017, Ryota announced his marriage to Michelle Lavigne, sister of Canadian singer-songwriter Avril Lavigne. Later that year, in October 2017, the couple welcomed their first child, a daughter.

On September 30th 2025, Ryota and Michelle shared that they had decided to go their separate ways as a couple, while continuing to support each other with respect and dedication as parents.

Outside of music, Ryota has a passion for photography. He frequently shares black-and-white photos on his social media accounts, showcasing landscapes, candid portraits, and behind-the-scenes glimpses of life on tour. His photography reflects an eye for detail and a creative approach, similar to his work as a musician.