"Kaihouku" is the first track on flumpool's newest album, "EGG," which came out on March 16th, 2016. The song was written by the group's lead singer, Ryuta Yamamura, and composed by guitarist Kazuki Sakai.

After the release of "EGG," flumpool is scheduled to go on an all-Japan tour called the "WHAT ABOUT EGGS?" 7th tour which will begin in April and culminate toward the end of June 2016. The tour which will include 14 cities and 22 performances.

"Kaihouku" is a song about opening up in the face of an uncertain future and unleash love, courage. In the MV, as the band plays through the song the world around them seems to slowly progress either towards freedom or insanity. Chess players develop superpowers and engage in combat, a sad man shelling eggs finds himself transported to a place in midst of the vast universe, and flumpool's speakers come to life and fly about like square, glowing angels. Much like their MV for "Yoru wa Nemureru kai?", the video ends with everything mysteriously back to normal.