Monami Kida can't remember the last time she had an argument with Hinano, her younger sister and partner in the classical-meets-pop project Kitri.

"It might have been a disagreement regarding the order of the songs we would play live," Monami, better known as Mona, says. "We have always been so close. When we were young, we would always play with dolls together, talk about everything together. Just always hanging out."

Hinano, or Hina, notes that's still true, to the point they share a room in their base of Kyoto.