
The members performed this song during one of the MCs at Request Hour. They were accompanied by their acapella coach who was the bass vocals for them, Yoshida Keisuke from INSPi. He was also responsible for the Oogoe Diamond acapella rendition performed by some members of AKB48 in AKB48 Kouhaku 2012.
Here is a stream to the particular MC!
http://v.youku.com/v_show/id_XNTA3NjUxNjg0.html
Alternate link: http://www.dailymotion.com/video/xx29q6_nmbyyyy_music#.UQVcbb9J6jb
Despite it being their first time performing an acapella, Yoshida Keisuke commended NMB48 on their Zetsumetsu performance, saying he was really moved and encouraged by them. He even complimented some of the notes Yamada Nana hit for this performance.
Sources:
SmilingSmling
metachan48
https://twitter.com/INSPi_keisuke

Omggg this was amazing and completely unexpected from a MC!!
Thinking they probably did this cause Zetsumetsu was unranked.
But sasuga NMB, imo, MVP for tonight :P
I have never been prouder as a fan.
*Almost died at Ainyan beatbox* hahaha.
Everyone did a great job though!!! Being amateurs and all, I was very impressed!