Saionji Hiro

Also Known As

SaiHi, Onji-san, Sai-kun, Hiro-kun, Kakkoii-kun


March 16, 1999 (Age 16)


Fukuoka, Japan


Japanese Pop


Singer, Dancer

Years Active

2013 - Present


HoshiBoshi Pro, @1 [former], H1GHFLY

Associated Acts

DreamS, NeXus, Polaris α, YUME, Baka Nikki

Saionji Hiro (西園寺ヒロ; born on March 16, 1999) is a former 1st Generation Little Ouji and sub-leader of Japanese pop group Luminus. He is also a voice actor.



On February 4, Saionji, alongside 14 other boys, succesfully passed the first auditions for HoshiBoshi Pro, making up the 1st Generation Little Oujis. 


On May 25, it was announced that Saionji alongside Akimoto Kureno, Yamagata Ryuu, Miyazono Takumi and Ayuzawa Kou, were to be members of the new group of HoshiBoshi Pro, Luminus. It was also announced that Akimoto will be leader since he was the oldest of the 5 members and Saionji as sub-leader. They debuted on June 26 with "Jinsei GAME".


On January 11, it was announced that he, along with the members of NeXus and other DreamS and Hoshi members, will be the cast of a new DreamS anime that will take Butterfly Days: Season 2's spot when finished in February, called "Baka Nikki". It will begin airing on February 1.


  • Name: Saionji Hiro (西園寺ヒロ)
  • Nickname: SaiHi, Onji-san, Sai-kun, Hiro-kun, Kakkoii-kun
  • Birthday: March 16, 1999 (Age 16)
  • Birthplace: Fukuoka, Japan
  • Blood type: B-
  • Height: 176cm (5"9)
  • HoshiBoshi Pro Status:
    • 2010-02-04: Little Ouji
    • 2013-05-25: Luminus Member
    • 2010-02-04: Member
  • Months in Luminus: 3 Months
  • Luminus Color: Red
  • Eastern Zodiac: Rabbit
  • Western Zodiac: Pisces
  • Charm Point: Eyes
  • Weak Point: Too serious and quiet at times
  • Strong Point: Is always reasonable
  • Favourite Animal: Lions
  • Special Skill: Violin, Pole Vaulting
  • Hobbies: Playing video games, practicing violin, practicing dancing
  • Favorite Food(s): Yakiniku, natto, meat
  • Least Favorite Food(s): Scallions, cauliflower, broccoli, taro
  • Favorite Color(s): Red, black
  • Favorite Sport: Pole Vaulting, 100m Hurdles
  • Looks up to: HI-5, JupiNus, Hey! Say! JUMP
  • Favorite Song: "Thrill" by Hey! Say! JUMP
  • HoshiBoshi Pro Groups:



  1. [2013.06.26] Jinsei GAME
  2. [2013.07.20] Cosmic Dreamer
  3. [2013.08.31] Super Delicate


  1. [2014.02.01] Baka Nikki (as Suzuki Rei)


  • He shows a disgusted face whenever he encounters disgusting things.
  • Is the youngest sub-leader in Hoshi.
  • He has a younger sister.
  • Practices a lot with dancing because he is not skilled at it (it was mention by Leader Kureno that he was always frustrated when he couldn't keep up when they were learning a new dance). 
  • Is one of the tallest members of Luminus.
  • Is known for his "my pace" character and cool prescence.
  • Is very good with Kanji.
  • Is said to be the most straightforward person you'll ever meet.
  • He is very skilled at playing the violin (he has been playing since the age of 4.)
  • Is currently learning how to speak english.
  • Akimoto says he finds it difficult getting birthday presents for Saionji because his and his older sister's (Akimoto Miharu's) birthday are just one day apart, and he doesn't have enough money to get them both presents.
  • His best friend is Akimoto Kureno.
  • His ideal girl is YUME's Matsumoto Yuuka.
  • When the members of Luminus were asked which member they never thought would become an idol, they all said Saionji. 
  • He is currently in his second year of high school.
  • He attends the same high school as Akimoto Kureno and Akimoto Miharu.
  • He has the deepest voice in Luminus.