- Name: Morimoto Ryutaro (森本龍太郎)
- Birthday: April 6, 1995
- Birthplace: Kanagawa Prefecture, Japan
- Blood Type: A
- Height: 171 cm
- Weight: 58 kg
- Shoe Size: 28 cm
- Admired senior: Takizawa Hideaki
- Hobby: reading Manga
- Type of Girl: Happy and not afraid to face any challenges.
- Favorite food: Spaghetti,fried food
- Dislike: Vegetables.
- Favorite animal: Hamster
- Favorite color:Yellow
- Favorite sport: Baseball
- Strong point: Noisy
- Weak point: Has a short memory.
- Favorite Song: "SHAKE" by SMAP
- Favorite TV Show:"Nakai Masahiro no Burakku Variety"
- Favorite Movie: "Hana Yori Dango"
Morimoto Ryutaro joined Johnny's Entertainment on August 12th, 2004 after he passed an audition for the Ya-Ya-yah variety program. In 2005 he was placed in the group J.J. Express and later was a member of the group Tap Kids. He debuted with the group Hey! Say! JUMP on September 24th, 2007.
On June 28, 2011, Japanese entertainment magazine Shunkan Josei published a story revealing that Morimoto was caught smoking a cigarette on camera. Images from the issue shows him smoking at 14 in January 2010 and at 15 in May 2010. When questioned, Morimoto stated that "it's fine, don't worry." Johnny's Entertainment quickly issued a public apology and planned to suspend all of Morimoto's activities indefinitely. He will not appear in SUMMARY 2011 and Hey! Say! JUMP will continue their activities as a nine member group now.
Around the begining of January 2012, it is was announced that Morimoto Ryutaro chose to pursue his studies and just continue to support Hey! Say! JUMP's activities even being not a member.
His younger brother Morimoto Shintaro is also a member of Johnny's Entertainment and together they are often called by fans "The Morimoto Brothers".
- He is the youngest member of the group Hey! Say! JUMP and is the youngest member to debut in the Johnny's industry at the age of 12.
- He currently has never had a specific solo in any Hey! Say! JUMP single because he usually takes the lower melody.
-  Juken no Kamisama as Saionji Yoshitsugu