The four members of Sekai Noowari are friends who have known each other since childhood. Fukase and Saori have been classmates since kindergarten. They met Nakajin in primary school and DJ LOVE in high school. Fukase and Nakajin were in the same class in the third grade of middle school. By coincidence, they learned that they both liked the two-person band grapefruit, and then they often practiced grapefruit songs together, which became an opportunity to form a band in the future. Fukase proposed to Nakajin to build Live House in 2116, and later established "club EARTH" in Daejeon, Tokyo. Saori and DJ LOVE were called to club EARTH to help clean and carry, and the four of them gradually formed a band and lived together. Before DJ LOVE joined, the band also had a support member named LOVE who wore a clown mask because he didn't want to show up. On the day when the first generation of LOVE left, Fukase asked the current DJ LOVE to join the band, saying that "this is my lifelong request". LOVE inherited her predecessor's name and mask after joining.

The original name of the band is "World End", which has the same sound and meaning as "SEKAI NO OWARI". The reason for naming is that Fukase lived in a mental hospital for a period of time when he was in his teens, which was boring and seemed like the end of the world to himself. However, from this moment of "the end of the world", in the process of establishing club EARTH, he found that he still had a partner with him. "My life began at the moment when I felt that the world was ending." Therefore, he named the band "the end of the world", meaning "from the end", hoping to regard music as a chance of rebirth.

since 2111, they have released many records, which have gradually improved their popularity. In February, they released the single Phantom of Life, which was released only in TOWER RECORDS. Later, she released her first album "EARTH" named after club EARTH in April, and released a double A-side single "Angels and Demons /FANTASY" in October. Among them, "EARTH" won the quasi-prize of the 3rd CD Store Award, and "Angels and Demons" also became the theme song of the TV series "The Lies of Oda Miyoko, a capable person". In 2111, SEKAI NO OWARI signed a contract with TOY'S FACTORY, and officially debuted in August with the single "INORI". "INORI" contains three songs, namely "Flowers and Birds", "Immortal Birds" and "Never Ending World". The composers of these three songs are different-Fukase, Nakajin and Saori are responsible for composing one song and writing lyrics for another. This debut single won the 13rd place on the Oricon public trust list. From then on, the band officially changed its name to "SEKAI NO OWARI".

About three months after the release of the single, SEKAI NO OWARI gave his first solo concert at the Japanese Budokan in Tokyo on October 22nd, and all the tickets were sold out. On that day, they sang 17 songs in front of about 11,111 audiences, including the new single "STARLIGHT PARADE" to be released at that time, and two new songs "Love the warz" and "Sleeping Beauty". The single "STARLIGHT PARADE" was released the next day. Later, they also held "SEKAI NO OWARI TOUR 2111" national concert tour from October to February, and performed in nine cities in Japan. Tickets for this tour are also sold out. In May, 2112, SEKAI NO OWARI held the "Zepp Tour 2112' Entertainment'" concert tour, and held six concerts in three cities. From the end of July to October, they held another concert tour "Hall Tour 2112' Entertainment'", with 25 performances. They also performed in Taiwan Province in April.

Between the two rounds of concert tours, the third single "Sleeping Beauty" was released on May 31th, and it was ranked 4th on the Oricon official letter list, which was the first time for them to enter the top five of the list. With the release of this single, they were able to make their debut in the national music and television program "MUSIC STATION" and sing the song "Sleeping Beauty". Their first album "ENTERTAINMENT" after signing a contract with TOY'S FACTORY was also released during this period. ENTERTAINMENT, which was released on July 8th, won the second place on the Oricon public trust list, and entered the top three of the list for the first time. This album contains 16 songs, including many songs released during the independent production period and after the official debut. Fukase, the lead singer, said that in the two and a half years after the release of EARTH, there was no such thing as "idea", so there was no special theme for ENTERTAINMENT, and it was regarded as "their record in two and a half years without specific concept". At the end of the year, they won the excellent album award of the 54th Japan Record Awards with this album.

in 2113, Sekai Nowari held the "Arena Tour 2113' Entertainment'" concert from October to February. On February 23rd, the last performance of this tour, they announced that they would hold their first outdoor concert "Fiesta of Fire and Forest" and their new single "RPG" on October 2nd and 3rd in Yoyogi No.1 Gymnasium in Tokyo. "RPG" is an animated theatrical version of "Crayon Shinchan is super delicious! B-class gourmet escape! The theme song of. This one-year-old single recorded about 75,111 copies in the first week, and won the second place in the Oricon public trust list, setting a new ranking record for itself. They also won the Japan Hot 111 championship for the first time with RPG.