Not to be confused with the unrelated artist Ryuu.
- Name: Ryutaro Nakahara (中原龍太郎)
- Birthday: October 1st, 1979
- Blood Type: O
- Birthplace: Fukuoka
- Likes: Visual design, arts, cartoon/anime, movies, video games, baseball, Japanese sake
- Dislikes: Persistence
Ryutaro Nakahara, better known as Ryu☆, first appeared in beatmania IIDX 4th style after winning a musicianship trial along with kors k, sanctioned by KONAMI for beatmania IIDX. He is currently one of the most active artists in BEMANI, having at least one new song for each new game on every active BEMANI series except for MÚSECA and ノスタルジア.
Ryu☆ is an artist and executive director in the EXIT TUNES music label, a sub-label of Pony Canyon, having some of his recent releases in BEMANI licensed through the label. Outside of BEMANI and EXIT TUNES, Ryu☆ regularly appears in the HARDCORE SYNDROME (HARDCORE TANO*C) series of albums, in Diverse System's AD:HOUSE, and in various releases of the S2TB Recording label. He has occasionally arranged songs of the Touhou Project series on the doujin label Yuuhei Satellite as well.
Ryutaro is known for being one of the most prominent figures in Japanese hardcore, dabbling into every hardcore genre, even speedcore. He's also proficient on dance music like bubblegum dance, handz up and lately, EDM, dubstep, and future bass.
Ryutaro is part of the Another Infinity duo with Xceon, where they've made themselves a name into J-POP as well, frequently collaborating with Mayumi Morinaga. Together, they have worked on a handful of songs for TV anime adaptations, including FAIRY TAIL, Yuyushiki, Occult Maiden, and Minami Kamakura High School Girls Cycling Club, among others.
- Ryutaro's primary alias, Ryu☆, is pronounced as "Ryusei" (sei/星 being "star" in Japanese).
- Ryutaro has provided a couple of works for TAITO's sound team, ZUNTATA.
- "The 4th" alias is a reference to the beatmania IIDX title both Kosuke Saito and Ryutaro Nakahara made their BEMANI debut in, beatmania IIDX 4th style.
- Ryu / Ryu☆ / Ryu*
- HHH (member of, with Dai and VJ Halka)
- 青龍 / 雷龍 / 紅龍 / 黒龍 / 白龍 / 機龍 / 星龍 / 月龍 / 電龍 / 日龍
- Vandalusia改 (member of, with Jun Wakita)
- Auridy (member of, with Dai.)
- Cream puff (member of, with moimoi and VJ Halka)
- Levaslater / Another Infinity (member of, with Starving Trancer)
- The 4th (member of, with kors k)
- #FFFFFF (member of, with DJ YOSHITAKA)
- starmine (2009)
- AGEHA (2010)
- Rainbow☆Rainbow (2011)
- Sakura Luminance (2012)
- Plan 8 (2013)
- BLUE DRAGON (2013, as 青龍)
- We're so Happy (2014)
- Seventh Heaven (2015)
- Ryu☆BEST -STARLiGHT- (2016)
- Ryu☆BEST -MOONLiGHT- (2016)
- AO-∞ (2017, as 青龍)
- Ryu☆BEST -SUNLiGHT- (2018)
- Rainbow Drop / AI (2003)
- Fly Into Dream / Rise And Fall (2005)
- Genbu (2009)
- Age Of The Moon (2009)
- Green Lightning (2010)
- The 4th EP (2012, with kors k)
- AO - EP (2015)
- ShiRo - EP (2016)
- The 4th EP2 (2016, with kors k)
- AO-0 (2016, as 青龍)
- Donkey Donk EP (2017)
- Murasaki-EP (2017)
- OOO EP (2017)
- O/D*20:EP (2018)
- 70min 70tracks 2018 (2018)
- BLUE FRACTAL (2018)
- Sakura Bloomin* (2019, with moimoi)