Al Najma After training at youth clubs in
Indonesia, Ryuji made his professional debut in
Bahrain with
Manama club
Al-Najma in a 20 August 2015 friendly match against
Malkiya Club. In this match, Ryuji was a starter who played 60 minutes before he was replaced. During this match, he received a yellow card in the fifth minute after a foul in the penalty area. Ryuji on 19 December 2015 scored his first goal for Al Najma in an away match against Al Tadamun Buri.
Arema FC After six months in Bahrain, Ryuji returned to Indonesia to join
Arema ahead of the unauthorized 2016
Indonesia Soccer Championship (ISC). As an apprentice to Arema's more senior players, Ryuji began to build his reputation as a physically robust defender who caught the attention of richer clubs at the end of the ISC. During a pre-season tournament ahead of the launching of the new
Liga 1 (Indonesia) top-flight competition, Ryuji left Arema after failing to win a starting position.
Persija Jakarta Rich club
Persija Jakarta saw Ryuji's Arema departure as a chance to develop the young defender's potential. On 3 February 2017, Ryuji accepted an offer to join his hometown club. Another reason was Ryuji wanted to play close to his Jakarta-based ailing father. Ryuji played in nine matches for Persija in the
2017 Liga 1 season, impressing coach
Stefano Cugurra who used him when senior players were on international duty. Despite its intention to keep Ryuji for the 2018 season, Persija let Ryuji play in
Thailand on loan for a year. This spell increased Ryuji's value, leading to a renewed contract in 2019 to guarantee his services. However, Ryuji went overseas again on loan from December 2020 as a byproduct of the
COVID-19 pandemic that stopped the
2020 Liga 1 season. Without certainty on when professional football in Indonesia could resume, Ryuji chose to take an offer to play for the newly promoted Malaysia Super League club
Penang for one full season.
PTT Rayong (loan) On 4 December 2017, Ryuji joined
Thai League 2 club
PTT Rayong on a one-year contract. His agent said one of the reasons that made Ryuji take the offer was the pay could help him finance his ailing father's medical treatment, indicating that Persija did not pay him as satisfactory. At Rayong, Ryuji developed into a more versatile player as coach
Teerasak Po-on often played the
center back as a
defensive midfielder. Ryuji played in 18 matches for Rayong and helped the club win the 2018 Thai League 2 season, earning it a promotion into
Thai League 1.
Penang FC (loan) Ryuji in December 2020 signed for
Penang to play in the
2021 Malaysia Super League season, on loan from
Persija Jakarta. On 6 March 2021, Ryuji made his debut for Penang on a league game against
Kuala Lumpur City, playing full 90-minutes as his team won 1-0.
Bali United On 13 January 2023, Ryuji signed a contract with
Liga 1 club
Bali United from Persija Jakarta.{{cite web |url=https://sport.detik.com/sepakbola/liga-indonesia/d-6510706/ryuji-utomo-gabung-bali-united-usai-dilepas-persija|title=Ryuji Utomo Gabung Bali United Usai Dilepas Persija == International career ==