Nisennenmondai (にせんねんもんだい) are a Tokyo, Japan-based instrumental rock trio who make music that's both raw and danceable in equal measure. They formed in 1999 and took their name from the Japanese translation of the then-current phrase "Year 2000 Computer Bug". Guitarist Masako Takada, bassist Yuri Zaikawa, and drummer Sayaka Himeno met at a club near their university and formed the band soon after. The band have mostly released music on their own Bijin label.