Formed in 2004 by two women called Ai — one a classically trained violinist whose hobbies include cooking, flower-arrangement and "home crafts," the other a "Star Wars" fanatic and lightning-speed MC — Japanese technopop duo Miami are releasing their debut mini-album after a year spent ricocheting between their home in Tokyo and tours in Korea, Vietnam, the United States and the United Kingdom.

Like Tokyo-based duo Kiiiiiii, Miami occasionally nod to their childhood in the 1980s. They employ a lot of childlike imagery, from the title and artwork to "Ace," the band's ending theme of children's anime "Gakkou no Kaidan." "Hello Basic" alludes to the joys of retro computing, and they clearly learned everything they ever wanted to know about hip-hop from the Beastie Boys.

But "Good Morning Playground" isn't a denial of the adult world. Assisted by producer Dr. Usui from Tokyo new wave/electro unit Motocompo, the arrangements are simple and catchy, but also edged with darkness, as in "Shiratama Disco," with its brutally repetitive disco beat, sinister synth backdrop and a looping violin refrain that results in a song equal parts J-pop duo HalCali and U.S. electropunks Suicide.