Ikimonogakari is a Japanese pop rock duo from Kanagawa Prefecture, originally formed as a trio in 1999. The group began with Yoshiki Mizuno and Hotaka Yamashita, who had known each other since elementary school where they both served as class animal caretakers, a role that inspired the band's name. Vocalist Kiyoe Yoshioka joined later that year. In 2021, Yamashita departed from the group, and Ikimonogakari has continued as a duo of Mizuno and Yoshioka. Mizuno serves as the primary songwriter and guitarist, while Yoshioka is the lead vocalist.

The band signed with Epic Records Japan, a label under Sony Music Entertainment Japan, and made their major debut in 2006 with the single Sakura. Their music is characterized by Yoshioka's emotive and powerful vocals, acoustic and pop rock arrangements often featuring guitar and harmonica, and lyrics that explore themes of nostalgia, everyday life, and resilience.

Ikimonogakari has contributed numerous songs to anime series, establishing a significant presence in the industry. Their first anime tie-up was the song Hanabi, released as their second major single on May 31, 2006. This track was used as the seventh ending theme for the long-running series Bleach. It debuted at number five on the Oricon Singles Chart, becoming the group's first top-ten single. The song was written by Yoshiki Mizuno and uses fireworks as a metaphor for fleeting memories.

The band is also widely recognized for their work with the Naruto franchise. Their single Blue Bird, released on July 9, 2008, was used as the third opening theme for Naruto Shippuden. The song is a fast-paced pop rock track that became one of their most successful singles, receiving multiple platinum certifications from the Recording Industry Association of Japan for digital sales. Another Naruto Shippuden opening theme performed by the group is Hotaru no Hikari, the fifth opening of the series, released as a single in 2009.

Ikimonogakari also contributed to the sports anime Big Windup!, performing the opening theme Seishun Line. This song was released as a double A-side single with Natsuzora Graffiti on August 8, 2007, and is included on their second major studio album, Life Album. As noted in the user query, they also performed Ryuusei Miracle, which was used for the anime Ghost Slayers Ayashi. This single was released on December 6, 2006.

In the following decade, the band continued to provide music for anime. Their song Netsujou no Spectrum was used as the first opening theme for the fantasy series The Seven Deadly Sins in 2014. After a period of hiatus, the group resumed activities and released the album WHO? in 2021, which includes the track Baku, the eighth opening theme for Boruto: Naruto Next Generations. In 2023, Ikimonogakari performed Tokimeki as the opening theme for the series Power of Hope: PreCure Full Bloom and Ureshikute as the ending theme for the film Pretty Cure All Stars F.

Beyond anime, the band's music has been featured in Japanese television dramas, films, commercials, and as theme music for NHK Olympic broadcasts. Their commercial success includes multiple number-one albums on the Oricon charts and several appearances on the prestigious NHK Kouhaku Uta Gassen music festival. Through their extensive catalog of theme songs, Ikimonogakari has become one of the most recognizable J-pop acts associated with anime music.