According to the band's official Facebook page, Kawashima died of a brain tumour. The wake and funeral will be private, but there will be a farewell event for fans at a later date.
In an official statement, Masayuki Nakano, the other half of the Boom Boom Satellites duo, wrote the following:
I imagine he is soaring around the world, finally freed from the restrictions of his body. His passing is not a tragedy, but the achievement of a lifetime goal and a happy ending. The love of our many fans supported Michiyuki Kawashima and Boom Boom Satellites on their journey, and we are truly happy and lucky because of you.
On behalf of Michiyuki Kawashima, I would like to thank all our fans and colleagues again.
Earlier this winter, it was announced that the group's EP "Lay Your Hands On Me" would be the group's final release, because of Kawashima's health.
At that time, Nakano stated, "Michiyuki Kawashima has now closed his life as a musician and is spending his days living peacefully with his family."
Boom Boom Satellites contributed music to anime like Appleseed, but also the Hollywood film The Dark Knight and the PlayStation Store. Most recently, the group's latest single "Lay Your Hands On Me" is the theme song for the anime Kiznaiver from Trigger.
May Michiyuki Kawashima rest in peace.