UNDER17 is a Japanese electronic music duo formed in 2001 by Haruko Momoi and Masaya Koike. The group specializes in synth-pop and electronic production, crafting distinctive "moe songs"—a subgenre characterized by cute, melodic vocal performances layered over digital instrumentation. Their sound blends J-pop sensibilities with electronic music production, creating an accessible yet technically sophisticated aesthetic.
The duo gained recognition through their work on anime soundtracks, including notable contributions to series such as Tenbatsu! Angel Rabbie, Popotan, and DearS. UNDER17's approach to electronic composition—combining catchy melodies with intricate synth arrangements—helped define the sound of early 2000s anime music and influenced subsequent generations of electronic and pop producers in Japan.