Question: Who was born first, Ryuichi Kawamura or Jason Scheff?

Context paragraphs:
Jason Scheff: Jason Randolph Scheff (born April 16, 1962, in San Diego) is an American bassist, singer, and songwriter.  From 1985 to 2016 he was the bassist and singer for the veteran pop-rock band Chicago.

Chicago 18: Chicago 18 is the fifteenth studio album by the American band Chicago, released on September 29, 1986.  As the successor to 1984's multiplatinum hit "Chicago 17", this album is the first without cofounding member Peter Cetera.  This is also the first album to feature Jason Scheff on bass guitar and vocals.

What Kind of Man Would I Be?: "What Kind of Man Would I Be?"  is a song written by Jason Scheff, Chas Sandford and Bobby Caldwell and recorded by the band Chicago for their 1988 album "Chicago 19" and 1989 album "Greatest Hits 1982–1989".  Scheff sang the lead vocals.

Inoran: Kiyonobu Inoue (井上 清信 , Inoue Kiyonobu , born on September 29, 1970 in Hadano, Kanagawa) , known exclusively by his stage name Inoran, is a Japanese musician, singer and songwriter.  He is best known as the rhythm guitarist and a co-founder of the rock band Luna Sea.  He started his solo career in 1997 and when Luna Sea disbanded in 2000, he formed Fake?  with Oblivion Dust vocalist Ken Lloyd a year later.  Then in 2005 when leaving Fake?  he founded Tourbillon with Luna Sea vocalist Ryuichi Kawamura and Hiroaki Hayama.  He has recently rejoined Luna Sea as they reunited in 2010, and in 2012 formed Muddy Apes with bassist Taka Hirose and support guitarist Dean Tidey, both from Feeder, and 8otto's vocalist Maeson.

Trip Trip: Trip Trip (stylised as trip trip) is Kokia's second album, released in January 2002.  It was her first album released with Victor Entertainment, and her only released under Gai Records management (though Kokia worked with both companies for her collaborations with Ryuichi Kawamura on his ЯKS album, "Kanata Made", in 2000).  Unlike "Songbird", the album was self-produced.

Break the Chain: "Break the Chain" is a song by Japanese rock band Tourbillon, and was the band's fifth and final single.  It was released a year-and-a-half following the release of their second album "A Tide of New Era", and was used as the opening theme for the 2008 television series "Kamen Rider Kiva".  Ryuichi Kawamura stated that the song was not just the "let's beat up the bad guys!"  kind of Kamen Rider Series opening theme, but a song that both children and adults can enjoy.

Aionism: Aionism is the third album released by the metal band Aion.  The first pressing released on October 8, 1991, included a sticker and cardboard slipcover.  A remastered version was released on June 6, 1995.  It is arguably the band's most successful album, reaching number 37 on the Oricon chart.  A promotional video for "Be Afraid" was made to promote the album.  Ryuichi Kawamura, vocalist of the rock band Luna Sea, provides background vocals for the song "Disarray".  Likewise every Luna Sea member does the same for the tracks "Launch Game", "S.S.S" and "Caution".

Chauncy (album): Chauncy is the 1996 debut solo album by singer/songwriter/bassist Jason Scheff.  Scheff is probably best known as a member of the band Chicago, where he has been the bassist and a lead singer since 1985.  It also featured the only officially available recording of his 1993 co-composition "Mah Jongg" prior to the release of the original Chicago recording in 2008.

Ryuichi Kawamura: Ryuichi Kawamura (河村 隆一 , Kawamura Ryūichi , born May 20, 1970 in Yamato, Kanagawa) is a Japanese singer-songwriter, actor and record producer.  He is best known as lead singer of the rock band Luna Sea.  After the group disbanded in 2000, Kawamura continued his successful solo career.  In 2005 he formed Tourbillon with fellow Luna Sea member Inoran and Hiroaki Hayama.  He has recently rejoined Luna Sea, as they reunited in August 2010.

Tourbillon (band): Tourbillon (トゥールビヨン , Tūrubiyon , French for "whirlwind") is a Japanese musical project formed in 2005 by Luna Sea members Ryuichi Kawamura (vocals) and Inoran (guitar), and D-Loop member Hiroaki "H. Hayama" Hayama (keyboards).

Supporting paragraphs: Ryuichi Kawamura Jason Scheff
Answer: Jason Randolph Scheff