Their initial music was considerably slower 'Natsu Koi' on Sakura Saku Machi Monogatari is considerably faster in tempo compared to the same song on Makoto ni Senetsu Nagara First Album wo Koshirae Mashita. Their primary instruments were the acoustic guitar, the electric guitar, and the harmonica. Ikimono-gakari's musical style stems from their original lounge rock style found on their first three mini albums under Cubit Club. She used to belong to a children theatrical company. She joined the band in high school when she suddenly saw Yamashita and Mizuno singing in front of the train station. Her nicknames are Yosshie, Kiyoe-chan and Kiyorasu (by Shouko Nakagawa). Her older brother was a classmate of both Hotaka and Yoshiki at high school. She is the band's lead vocalist, and has written lyrics to some of the band's songs. She is a graduate of Ebina High School and the Showa Academia Musicae Junior College.

Kiyoe Yoshioka (吉岡聖恵, Yoshioka Kiyoe?, born February 29, 1984) is from Atsugi-shi, Kanagawa Prefecture. He has also written lyrics and melodies to some of the band's songs. He is the leader of the band, and plays the guitar and vocals. He is a graduate of Atsugi High School and the Faculty of Social Sciences, Hitotsubashi University. Yoshiki Mizuno (水野良樹, Mizuno Yoshiki?, born December 17, 1982) is from Ebina-shi, Kanagawa Prefecture. He plays the guitar and harmonica, and has written lyrics and melodies to some of the band's songs. He is a graduate of Atsugi High School and the Faculty of Social Sciences, Hosei University. Hotaka Yamashita (山下穂尊, Yamashita Hotaka?, born August 27, 1982) is from Ebina-shi, Kanagawa Prefecture. The band was formed in Kanagawa Prefecture in February 1999 by Hotaka Yamashita and Yoshiki Mizuno, and was later joined by lead vocalist Kiyoe Yoshioka in December the same year. They are part of Sony Music Japan's EPIC Records label. Ikimono-gakari (いきものがかり, ikimono-gakari?) is a Japanese rock band.

Ikimonogakari