Question: Which of these bands has had songs featured in several anime series, U2 or Flow?

full_context: Document 1: U2 discography: The discography of Irish rock band U2 consists of thirteen studio albums, one live album, three compilation albums, sixty-seven singles, and eight extended plays (EPs). The band formed at Mount Temple Comprehensive School in 1976 as teenagers. In 1979, the group issued their first release, the EP "U2-3", which sold well in Ireland. The following year, the group signed to Island Records and released their debut album, "Boy". It reached number 52 in the UK and number 63 in the US. They followed it up with the release of "October" (1981) and "War" (1983). "War" was a commercial success, becoming the band's first number-one album in the UK while reaching number 12 in the US. The album yielded the singles "Sunday Bloody Sunday" and "New Year's Day" and have since become among the band's most popular songs. On the subsequent War Tour, the group recorded the live album "Under a Blood Red Sky" and concert film "", both of which sold well and helped establish them globally as a live act.
Document 2: SMAP discography: The discography of Japanese boy band SMAP consists of 21 studio albums, 5 compilation albums, 23 video albums, and numerous singles. Sports Music Assemble People, abbreviated as SMAP, was formed in 1988 by a group of backup dancers for the boy band Hikaru Genji of Johnny & Associates. The band's initial releases performed poorly on the charts, but the following ones started gaining attention, aided by the group's appearance on their own variety show, "SMAP×SMAP". Their 2003 single "Sekai ni Hitotsu Dake no Hana" sold over two million copies in Japan, becoming one of the best-selling singles in the country. In August 2016, the group announced that they will disband by the year end. Since 2003, all of the band's releases have peaked at number one on the Oricon Albums or Singles Chart. The group has sold over 35 million records in Japan.
Document 3: Flower (Japanese band): Flower is a Japanese pop girl group formed by LDH in 2009 and signed to Sony Music Japan. They are a dance and vocal unit of collective girl group E-girls alongside Dream and Happiness. The group consists of one vocalist and five performers.
Document 4: War Tour: The War Tour was a concert tour by the Irish rock band U2, which took place in 1982 and 1983 in support of the group's third album "War". The tour took place in Western Europe, the United States, and Japan, with new material from "War" taking an increasing role as the tour progressed. Venues were mostly halls, but some arenas were introduced later on. U2's performances were very well received both critically and commercially, especially in the United States where U2 broke through to become a major act. Scenes of lead singer Bono waving a white flag during the song "Sunday Bloody Sunday" became an emblematic image of this phase of U2's career. It was their first tour as full-time headlining act and their first to be profitable.
Document 5: Sphere (Japanese band): Sphere is a Japanese pop idol group made up of voice actresses who are all managed by Sony Music Entertainment's Music Ray'n subdivision, under the Lantis music label GloryHeaven. The group debuted in April 2009 releasing their first single "Future Stream", which was followed up with the June 2009 release of "Dangerous Girls" theme used in the opening animation of the PlayStation Portable game "Ken to Mahou Gakuen Mono 2" (known in the US as "Class of Heroes 2"). As all four are voice actresses, their music is frequently featured as theme songs to a variety of anime series, including "First Love Limited", "Sora no Manimani", "Demon King Daimao", "Asobi ni iku yo!" and "Ryūgajō Nanana no Maizōkin". The group features in the anime "Natsuiro Kiseki", in which every member has a role as the four main characters. On March 4, 2017, the group announced to refrain from any group activities such as releasing new singles or doing concerts after their 2017 national tour ended, until the group's 10th anniversary in 2019. The members will keep doing their voice acting works and solo activities.
Document 6: Flow (band): Flow is a Japanese rock band, formed in 1998 and signed on to Sony Music Japan's Ki/oon Music label. Flow is a five-piece band made up of two vocalists, a drummer, a bassist, and a guitarist. As of February 2017, the band has released 31 singles and 10 studio albums. Their songs have been featured in the opening sequences of several anime series.
Document 7: Hey! Say! JUMP discography: The discography of Hey! Say! JUMP features five studio albums, twenty singles and twenty-eight music videos, all released through J Storm. The group activities started when the temporary five-member group Hey! Say! 7 were put together to provide the theme song for the anime Lovely Complex. The original members were Yuya Takaki, Daiki Arioka, Ryosuke Yamada, Yuto Nakajima, Yuri Chinen. The five Hey! Say! 7 members were later joined by another four idols thus creating the group Hey! Say! JUMP, the agency's largest group in history. The group made their CD debut through "Ultra Music Power" which topped the Oricon singles chart. Hey! Say! JUMP released their first full length studio album, "JUMP No. 1" on July 7, 2010.
Document 8: U2 360° Tour: The U2 360° Tour was a worldwide concert tour by rock band U2. Launched in support of the group's 2009 album "No Line on the Horizon", the tour visited stadiums from 2009 through 2011. The concerts featured the band playing "in the round" on a circular stage, allowing the audience to surround them on all sides. To accommodate the stage configuration, a large four-legged structure nicknamed "The Claw" was built above the stage, with the sound system and a cylindrical, expanding video screen on top of it. At 164 ft tall, it was the largest stage ever constructed. U2 claimed that the tour would be "the first time a band has toured in stadiums with such a unique and original structure."
Document 9: Zoo TV Tour: The Zoo TV Tour (also written as ZooTV, ZOO TV or ZOOTV) was a worldwide concert tour by rock band U2. Staged in support of their 1991 album "Achtung Baby", the tour visited arenas and stadiums from 1992 to 1993. To mirror the new musical direction that the group took with "Achtung Baby", the tour was intended to deviate from their past and confound expectations of the band. In contrast to U2's austere stage setups from previous tours, the Zoo TV Tour was an elaborately staged multimedia event. It satirised television and media oversaturation by attempting to instill "sensory overload" in its audience. To escape their reputation for being earnest and overly serious, U2 embraced a more lighthearted and self-deprecating image on tour. Zoo TV and "Achtung Baby" were central to the group's 1990s reinvention.
Document 10: Larry Mullen Jr.: Laurence Joseph Mullen Jr. (born 31 October 1961) is an Irish musician and actor, best known as the drummer of the Irish rock band U2. Mullen's distinctive drumming style developed from his playing martial beats in a childhood marching band, the Artane Boys Band. Some of his most notable contributions to the U2 catalogue include "Sunday Bloody Sunday", "Pride (In the Name of Love)", "Where the Streets Have No Name", "Zoo Station," "Mysterious Ways", and "City of Blinding Lights".
Document 11: One Ok Rock discography: Japanese rock band One Ok Rock has released eight studio albums, two EPs, 22 singles, seven video albums, six cover versions, and 32 music videos. One Ok Rock was formed in Tokyo, Japan in 2005, currently consists of Takahiro Moriuchi (vocals), Toru Yamashita (guitar/leader), Ryota Kohama (bass), and Tomoya Kanki (drums).
Document 12: PopMart Tour: The PopMart Tour was a worldwide concert tour by rock band U2. Launched in support of the group's 1997 album, "Pop", the tour's concerts were performed in stadia and parks in 1997 and 1998. Much like the band's previous Zoo TV Tour, PopMart was elaborately staged. Its lavish stage design had a 165 ft wide LED screen, a 100 ft -high golden arch, and a large mirror-ball lemon. As with the Zoo TV tour, the band delivered an image and performance that were ironic and self-mocking, deviating from its earnest performances of the 1980s; the band performed in costumes that, along with the PopMart stage design, poked fun at the themes of consumerism and pop culture.
Document 13: U2: U2 are an Irish rock band from Dublin formed in 1976. The group consists of Bono (lead vocals and rhythm guitar), the Edge (lead guitar, keyboards, and backing vocals), Adam Clayton (bass guitar), and Larry Mullen Jr. (drums and percussion). Initially rooted in post-punk, U2's musical style evolved throughout their career, yet has maintained an anthemic sound built on Bono's expressive vocals and the Edge's effects-based guitar textures. Their lyrics, often embellished with spiritual imagery, focus on personal and sociopolitical themes. Popular for their live performances, the group have staged several ambitious and elaborate tours over their career.
Document 14: One Ok Rock: One Ok Rock, stylized as ONE OK ROCK (pronounced in Japanese as "one o'clock"), is a Japanese rock band formed in Tokyo, Japan in 2005. The band currently consists of Takahiro Moriuchi (vocals), Toru Yamashita (guitar/leader), Ryota Kohama (bass), and Tomoya Kanki (drums).
Document 15: U2 by U2: U2 by U2 is an autobiography written by the members of Irish rock band U2 and first published in London by HarperCollins in 2005. Bono, The Edge, Adam Clayton, and Larry Mullen Jr. collaborated with their friend Neil McCormick, a staff music writer for "The Daily Telegraph" to write the only authorized biography of the band. It portrays the story of U2 in their own words and pictures.
ground_truth: Flow