LEO was born in Yokohama in 1998 as Leo Konno. He started playing the koto at the age of 9. He studied under Curtis Patterson, a music teacher and koto player, and later under Kazue Sawai, a respected Japanese koto player. At the age of 16, he became the youngest ever winner of the Grand Prize and the MEXT Award at the Japanese Hogaku Music Competition in Kumamoto. This brought him into the limelight and made his major debut in 2017 at the age of 19.

LEO has appeared in many media such as the MBS documentary program 'Jounetsu Tairiku', TV Asahi's 'Untitled Concert' and 'Tetsuko's Interview'.

He has performed as a soloist with conductors including Sebastian Weigle, Michiyoshi Inoue, Kazuyoshi Akiyama, and Nodoka Okisawa, as well as with the Yomiuri Nippon Symphony Orchestra, the Tokyo Philharmonic Orchestra, Kyoto Symphony Orchestra, and Kanagawa Philharmonic Orchestra.

In 2019, he received the Idemitsu Music Award and the Kanagawa Culture Award Future Prize.

In 2021, he performed the world premiere of a newly commissioned koto concerto composed by Dai Fujikura, with the Yomiuri Nippon Symphony Orchestra conducted by Masato Suzuki.

In 2022, he performed at Blue Note Tokyo, the first time for a koto player, and also made an unprecedented appearance at SUMMER SONIC, attracting attention for his new genre-defying attempts.

He has been attracting a great deal of attention and high future expectations as a young talented koto performer who is pursuing the new appeal of the koto while still deeply respecting the tradition.